1

UNESCO-NIGERIA TECHNICAL & VOCATIONAL EDUCATION

REVITALISATION PROJECT-PHASE II

YEAR I- SE MESTER I

THEORY

Version 1: December 2008

NATIONAL DIPLOMA IN

CIVIL ENGINEERING TECHNOLOGY

CONSTRUCTION MANAGEMENT

COURSE CODE: CEC242

2

COURSE INDEX PAGE

WEEK ONE

1.0 INDUSTRIAL DEVELOPMENT AND REVOLUTION 1 1.01 Bronze Age 1 1.02 The Iron Age 1.03 The Middle Age 2 1.04 Industrial Revolution-19th Century 3 1.05 Atomic, Nuclear and Space Era-20TH Century 3 1.06 Computer and Information Age (1950-Date) 4 1.20 Evolution of Technological Civilizations 4 1.30 Indices of developed society 5 1.31 Energy Supply 6 1.32 Transportation System 7 1.33 Communication system 7 1.40 Summary 7

1.50 Nomadic and Past Nomadic Era 7

WEEK TWO

2.0 EVOLUTION OF MANAGEMENT 9

2.01 19th Century 10 2.02 20th Century 10 2.10 Scientific Management 11 2.11 Objectives of Scientific Management 12 2.12 Principles of scientific management 12 2.13 Advantages of scientific management 12 2.14 Some Aspects of Scientific Management 14 2.15 Non Human Aspects 16 2.20 FREDERICK .W. TAYLOR (1856-1917) 17 2.30 HENRY LAWRENCE GANTT 1861-1919 19 2.40 HENRI FAYOL (1841-1925) 20 2.50 FRANK GILBRETH (1868-1924) 22 2.51 The One Best Way: 23 2.52 Motion Study 23 2.53 Time Study 23 2.54 Three-position Plan of Promotion 23 2.60 ELTON MAYO (1880-1949) 24 2.70 The role of Civil Engineer in National Development 25

3

WEEK THREE

3.0 MANAGEMENT FUNCTIONS (PROCESSES) 26

3.01 Definition of Management 26 3.10 Management Functions 26 3.11 Planning 27 3.12 Organising 27 3.13 Controlling 28 3.14Staffing 28 3.15 Motivation 28 3.16 Effective communication 29

WEEK FOUR

4.0 DESIGNING AN ORGANIZATION 30

4.01 Meaning of Organization 30 4.10 Kinds of Organization 30 4.11 Formal and Informal Organizations 30 4.20 Organization Charts 31 4.21 Organization chart 31 4.30 Organization Structure 32 4.40 Forms of Organization 33 4.41 Line Organization 34 4.42 Line and Staff Organization. 34 4.5 Authority Relationship 35 4.51 Line Authority 35 4.52 Staff Authority 35 4 .53 Functional Authority 35 4.60 Authority and Responsibility 35 4.70 Power and Influence 36 4.80 Sources of Authority 37 4.81 Institutional Source 37 4.82 Subordinate-Acceptance source. 37 4.90 Limits of Authority 38 4.91 Level in the Organization 39 4.92 Superior Authority 39 4.93 Subordinate Acceptance 39

WEEK FIVE

5.0 Parties To Civil Engineering Contracts And Their Inter Relationships 5.01 Client 41 5.02 Consultant 41 5.03 Contractor 42 5.10 Contract Documents 43 5.20 Statement of the Scope of the Contract 49 5.30 Data affecting the execution of the works. 49

4

WEEK SIX

6.0 Types And Scope Of Civil Engineering Contracts 6.10 Bills of Quantities Contract 50 6.20 Schedule-of-Rates Contracts 52 6.30 Lump-sum Contracts 54 6.40 Cost-plus percentage Contract 55 6.50 Cost-plus Fixed-fee Contract 56

6.60 Package-deal (All-in) Contract 57

WEEK SEVEN

7.0 Student Excursion 58 7.1 Visit a construction site 58

WEEK EIGHT

8.0 PROJECT PLANNING AND COST CONTROL 59 8.1 Project Planning-Network Techniques 60 8.2 Deterministic Project Planning (CPM) Preparation 60 8.21 METHODS OF PREPARING A (CPM) NETWORK 60 8.30 The Elements of an Activity on- an -Arrow Network 61 8.40 Principle of Dependency 62 8.41 Merge Event & Burst Event 62 8.42 Common Errors in Logicality of Network Diagrams 63 8.43 Dummy Activity 64 8.44 Identify Dummies 66 8.45 Logic Dummies 66 8.50 Network Construction 66 8.60 Activity Duration 67 8.61 Project Duration 68 8.62 Application of NWT 68 8.63 Limitations 68 8.70 Technique OF Estimation 69

WEEK NINE

9.0 MATERIAL QUALITY CONTROL MEASURES 9.01 Concrete 74 9.02 Cement 75 9.03 Water 75 9.04 Admixtures 75 9.1 Mixing 76 9.2 Transportation 76 9.3 Placement 76 9.4 Curing 77 9.5 Property Monitoring 77

5

9.6 Reinforcing Bars 78 9.7 Structural Steel 78 9.8 Timber 79

WEEK TEN 10.0 Concrete Mix Design 80 10.1 Definition 80 10.11 Purpose of Mix design 80 10.12 Objects of Mix design 80 10.13 Factors affecting the choice of mix proportion 81 10.2 Types of cement 81 10.21 Maximum nominal size of coarse aggregate. 82 10.22 Grading of combined aggregate 82 10.23 Water / Cement ratio 83 10.24 Workability 83 10.25 Durability 83 10.26 Quality Control 83 10.30 Grades of concrete and requirements for structures and general construction 84 10.40 Methods of Concrete Mix Design 85 10.50 The Department of Environments Design (DOE Method) 86 10.51 Step – by – Step Procedure to DOE mix design 86 10.6 Determination of cement content 87 10.61 Determination of Total Aggregate Content 88 10.62 Determination of Fine Aggregate 88 10.7 Worked example as class-room demonstration 89

WEEK ELEVEN

11.0 Construction Machine, Plants and Labour 92 11.01 Introduction 92 11.1 Classes of Mechanical Equipment 93 11.2 General Factors in the Selection of Construction Equipment 94 11.3 Selection Process 95

WEEK TWELVE

12.0 Earth Moving Equipment 96 12.10The Utilization of Earth-Moving Equipment 96 12.2 Fundamentals of Earth-Moving 97 12.3 Materials 97 Swell Load Factor Compatibility

WEEK THIRTEEN

13.0 Maintenance 103 13.1 Introduction 103 13.2 Maintenance Department 103 13.3 Breakdown Maintenance 105

6

13.4 Preventive Maintenance 105 13.5 Functions or Element of Preventive Maintenance 106 13.6 Advantages of Preventive Maintenance 108 13.7 Maintenance Procedure 108 13.8 Requirements for Good Preventive Maintenance 109

WEEK FOURTEEN

14.0 Effective Methods Of Transferring Knowledge And Skills To Subordinates 111 14.01 Introduction 111 14.02 Parties Involved in the Transfer Process 111 14.20 Principles of Knowledge and Skill 112 14.30 Transfer by Engaging the Principles of Effective Supervision 113 14.40 Transfer by Engaging the Principles of Effective Scientific, Technical and Technological Teaching 114 Conclusion 115

WEEK FIFTEEN

15.0 INTRODUCTION AND DEFINITIONS 122 15.1 Definition of some Accounting Terms 122 15.11 Book-Keeping 122 15.12 Financial Accountant 122 15.13 Business 122 15.14 Transaction 122 15.15 A Cash Transaction 122 15.16 A Credit Transaction: 122 15.2 Starting a Business 123 15.21 Assets 123 15.22 Fixed Assets 123 15.23 Current Assets 123 15.24 Purchases 123 15.25 Sales 124 15.26 Stock 124 15.27 Liabilities 124 15.28 Current Liabilities 124 15.29 Long Term Liabilities 124 15.30 Capital 124 15.31 Drawings 125 15.32 Accounting Equation 125 15.3 Double Entry System 126 15.4 An Account 126 15.5 Features of an Account 126 15.6Steps to follow in According by the Double Entry System 127 15.7 Double Entry and Accounts 131 15.8 Classification of Accounts 133 15.81 Personal Accounts 133

7

15.82 Impersonal Accounts 133 15.83 Real Accounts 133 15.84 Nominal Accounts 133 15.9 Rules for Entering up personal Accounts: 133 15.10 Rules for Entering up Real Accounts 134 15.11 Rule for Entering up Nominal Accounts 134 15.12 Division of the Ledger 134 15.12:1 Ledger 134 15.13 Division of the Journal 136

8

WEEK ONE 1.0 INDUSTRIAL DEVELOPMENT AND REVOLUTION

Man’s social structure was transformed from the wandering nomadic to organized

settlements or post nomadic era. This developed out of the need to have agricultural

communities and protection for each other. The soil cultivation resulted in the sudden

stoppage of wandering and of periodic food supply.

This agricultural discovery, however, brought about rough division of labour whore

man does the heavier task while the wife and children do the lighter domestic tasks. The

development of settlements brought out the creation of new ideas and needs of the society in

terms of security, organization and efficiency in doing things. This led to a more efficient

system of production and occupational division of labour and introduction of trade by barter;

this development however resulted into the formation of what is now called the market place

where exchange of surplus food and other items takes place.

1.01 BRONZE AGE

Man’s bare hands were his first tool followed by wood, bones, stones and metal tools

in this order. However this premature age pored way for more technical activities in the

bronze age where bronze, alloy of tin and copper, was man’s first hard metal, utilized in the

making of weapons, tools and other domestic utilities. Some typical examples of tools

developed in this era include the following: Bows, arrows, axes, spoons, cutlasses, knives,

chisels, gorges, razors, boats and chariots.

Other technical innovations in this era is the introduction of the tongs for handling hot

metals, bellows for metallurgical processes and development of wax process for castings.

Infact, the first technological revolutions ended with the bronze age by the year 2500 BC.

1.02 THE IRON AGE

The first solid metal called iron was accidentally discovered by a man who saw

glooming show from a stone in fire, which produced a solid black form after cooling.

9

Cooking utensils made from clay was developed out of the need to store and cook cereals.

The development of textile machines for spinning cotton, wool and the looms for weaving

materials. The need to meet the growing human population as a result of limited animal skin.

The periodic flooding of the valleys of the river Nile in Egypt, Indus in former India, the

Mesopotamia in Iraq gave birth to the idea of irrigation which subsequently enhance food

production and improved cropping.

However, the development and growth of settlements, cities & towns led to the birth

of auxiliary services emanating from agriculture, such as black & white smiths, wheel

wrights, shoe makers and plough makers, builders and tails. More so, the idea of labour

division brought about specialization in smelting, casting, working in copper and the

formation auxiliary occupation like bakery and brewing. The use of ox-drawn plough and

wheel cart started in the Indus valley about 2,300-1, 700 BC.

Later, the tribesman in the mountains of Armania discovered the use of heavier and cheaper

steel utilized to produced tools and weapons as a substitute to the rate and costly light bronze.

Iron tools made possible the cutting of funnels, building of bigger and better ships and

weapons.

The idea of technological societies started with the independent craftsman in athons

who grouped together and were recognized as a specialized technical field.

1.03 THE MIDDLE AGE

This era saw the collapse of Roman Empire, most agricultural communities became

self-reliant. Technological innovations were further resuscitated when scholarship was added

to manual labour. In other to protect injurious artisanship, sort of regulatory bodies called

slide were formed. The slides boosted incentives to invent and improve the then existing

technologies by adopting and developing and developing borrowed techniques and

technologies.

This period also saw the birth of trade fairs that boosted technological innovations and

developments. This later resulted into a religious fair of modest honest trading.

This religious fair in the twelfth century (1200AD) took advantages of its location in

Germany and centrally developing Europe which brought about exchange of technological

ideas and inventions from all over the world. These ideas and inventions of many diverse

cultures were welded together in Europe to create a foundation for the new technological

modern society which was the spring board of the later industrialized revolution. Invention

10

and developments of this age include water wheel, wind wills. Steering ships with rudder and

compass instead of ears & sails, improved ploughs, clocks, printing technology and so forth.

This is the age of important scientific discoveries, trade, acquisition and adoption of

technologies from about 1450-1660 AD.

1.04 INDUSTRIAL REVOLUTION-19 th CENTURY

Industrial revolution started in the 19th century and still remains the hallmark of the

modern technological civilization. The economy and social system of the era contributed

principally to the great achievements of that time. In their era influence, power and money

are acquired mainly by technological means. There were more profit and spectacular increase

in the standard of living as a result of increased national turn over. During this period, there

was a great shift of energy/.technological orientation from scholarly theories about the

universe to research and development relevant to domestic economic growth. More also,

trade in real business commenced and other contrivances such as wheel, steam engine,

steamship, and radio were made.

1.05 ATOMIC, NUCLEAR AND SPACE ERA-20TH CENTURY

This era saw the exploration of space pioneered by a Russian, Konstantin k.

Tsiokorsky and an American called Robert h. Goddard and a German, Herman Oberth. In this

era, Solviet launched it first artificial satellite into the earth orbit in 1957, three months

America launched Explorer 1 in 1961, subsequent after the launche of Sputruk 2 with a line

dog to prove man’s survival in the space by the missions. In 1969, American astronauts Neil

Armstrong and Edwin.E. Aldrim of Apollo II lunar module became the first humans to set

foot on the moon on 20th July of that year.

Further studies saw the exploration of the moon, stars, mercury and other planets to

collect samples for study of possibility of life. These discoveries has led to the launching of

better meteorological and communication satellite in our orbit and space leading to improve

defence and communication services.

Development in this era indicated the use of Atomic energy during the second war when

American dropped atomic bomb on the Japanese cities of Hiroshima and Nagasaki with over

200,000 people killed and thousands ruined in 1945.

11

However, recent studies into Atomic and Nuclear energy shows that it could be used for

generating an alternative power supply but with harmful by product which could be used to

make nuclear weapons. The disastrous of nuclear power plant in the then USSR in 1986,

which saw the maiming of many people, exemplified the negative aspect of nuclear energy

utilization.

1.06 COMPUTER AND INFORMATION AGE (1950-DATE)

Computer, the major device for data and information manipulation and transfer was first

recognized when sticks and ropes were used as first analog computer device. However, the

modern computers evolved from the mid-twentieth century-1950’s ranging from the vacuum

tube relays to transistors; to small scale integrated circuits (IC) to the initial large scale IC’s

such as Pentium II & III which are now connected to form networks. The networks are

interconnected to form internet. The present information super highway makes the world link

together in a manner never imagined before. Through this interconnected networks, products,

services, information and ideas of various technological innovations are shared worldwide

with much better efficiency, leading to the rapid changing technological achievements

presently. More so, recent development into software and micro chips has led to more

advance operation in the ICT world with smaller apertures capable of storing larger

information than before and also the emergence of OS (operating system) like Microsoft XP,

and other windows products.

1.20 Evolution of Technological Civilizations

Matter and the earth formations, are all due to technology. There isn’t a single exception to

this basic fundamental truth. Is there any?

The basic reality of life is that the history of civilization of mankind and that of Nations are

all related in one way or the other to engineering and also technology.

Anthropologists have recently formulated a theory of cultural evolution in which human

developments has three stages of savagery, barbarism and civilization .A close observation of

our environment reveals that technological development started from the time of creation to

the present day super technological breakthrough and achievements.

12

In all these giant strides in the evolution up to the present day society, there is one discipline

that runs parallel or the prime motivator of human development and this is Engineering or

Technology.

1.30 Indices of developed society

As enunciated earlier in a somewhat different form, civilization is a condition of human

society characterized by a high level of cultural and technological achievements and

corresponding complex society and political development.

Throughout the history of human growth and development, there are three indices that

indicate a civilized and developed society. Whichever society has high standard performance

of all the three parameters is necessarily a developed society.

These three indices of development are:

i. Energy Supply

ii. Transportation System

iii. Communication system

Any society or nation that has sufficient and reliable Energy supply, Transportation, and

communication systems is necessarily developed. Apply these parameters to any of the

advanced nations and the result will be confidently positive. But the very low developed

nations will rate low in any of three indices above . Every modern society is tied together by

these three infrastructures. The interaction of these systems makes possible the emergence

and development of societies. Engineering/Technology, of course, is the essential factor in

shaping these infrastructures.

In Nigeria, much of these strategic and vital infrastructures are all based 0n foreign

technology due to the non-optimal utilization of human resources available in engineering

field. A few examples are given to buttress Nigeria’s overdependence on foreign technology.

(Gulma)

1.31 Energy Supply

Table 1.31 The Eight NEPA Generating Stations

S/No. POWER

PLANT

CAPACITY

(MW)

TYPE OF

PLANT

SUPPLIER COUNTRY

OF ORIGIN

1. KAINJI 760 HYDRO GEC U.K.

13

ASEA

HITACHI

VOEST ALPINE

SWEDEN

JAPAN

AUSTRIA

2. JEBBA 540 HYDRO VOEST ALPINE

HITACHI

AUSTRIA

JAPAN

3. SHIRORO 600 HYDRO GEC

VOEST ALPINE

CHAST-MAIN

U.K.

AUSTRIA

U.S.A.

4. EGBIN 1320 STEAM HITACHI JAPAN

5. SAPELE 1020 STEAM (720)

GAS

TURBINE

ABB(ASEA

BROWN

BOVERI)

GERMAN

SWEDEN

SWISS

6. AFAM 700 GAS

TURBINE

ABB(ASEA

BROWN

BOVERI)

GERMAN

SWEDEN

SWISS

7. DELTA 876 GAS

TURBINE

G.E. U.S.A

8. IJORA 60 GAS/DIESEL G.E. U.S.A.

TOTAL=5876MW=6GW

THE WORKS INVOLVED

1. CIVIL WORKS *ALL SUPPLIERS ARE FOREIGN

2. ELECTRO-MECHANIC * ALL OVER-HAULINGS ARE FOREIGN

3. SUB-STATION * MINOR MAITENANCE ARE DONE BY

NIGERIANS

4. PROTECTION GLASS

Conspicuously, it can be seen that many of the generating plants at any state of the

construction, that is the civil work, mechanical/electrical, and the safety control are nearly all

foreign. Infact, even the overhauling is being done by foreign experts. The same applies in

the Turn Around Maintenance (TAM) of all the refineries, Aluminum Smelting Company

(ALSCON), Ikot Abasi, and the steel rolling mills.

1.32 Transportation System

14

The available traveling modes in Nigeria include the roads, railways, inland waterways, the

ocean liners, and airplanes. None of these traveling modes are in adequate capacity or

available at all hours. At nights, traveling is generally unsafe and fuel availability for sale is

almost nil. These hazards and inconveniences of, generally, all night distant journeys are

clearly manifestations of under-development.

1.33Communication system

Anyone who a travel to any part of the developed society knows what good

communication network is, a telephone is assured all times. By the time the last digit of

number being called is pressed, the line through unless it is ready engaged. Telephone and

cellular mobile units are available in few major cities and towns in Nigeria. But the system

failure is rampant. Towns with analogue telephone connections are difficult to reach.

Furthermore, available lines are severely limited.

1.40 Summary

Summarily, it is the emergence of effective and reliable energy supplies, transportation, and

communica5tions that make a developed society. One can look at the setting in any of the

well-developed nations and one could clearly observe the high standards in all of these three

determinant characteristics.

1.50 Nomadic and Past Normadic Era

Right from the time of the existence of man on the earth, began the quest by man to

combat the harsh conditions of the environment to meet the basic need of food, clothing and

shelter. Man began to hunt for animal flesh and gather fruits as food, animal skin and plant

fig as clothes, plant and physical shades for shelter.

This trial and error approach led to the accidental discovery of domesticated animals which

led to the organized agricultural practice of sowing, planting and reaping. Fire was

discovered so that food can be cooked rather than eaten raw or dried.

Man’s social structure was transformed from the wandering nomadic to organized

settlements or post nomadic era. This developed out of the need to have agricultural

communities and protection for each other. The soil cultivation resulted in the sudden

stoppage of wandering and periodic food supply.

This agricultural discovery brought about rough division of labour where man does the

heavier task while the wife and children does the lighter domestic tasks. The settlement

development brought out the creation of new ideas and needs of the society in terms of

security, organization and efficiency in doing things. This led to a more efficient system of

15

production and occupational division of labour and introduction of trade by barter. Markets

were formed for the exchange for surplus food and other items.

16

WEEK TWO 2.0 EVOLUTION OF MANAGEMENT

Management is the basic, integrating process of business activities that surround our daily

life. It may be defined as achieving results by coordinating the activities of other people. It is

concerned with the proper use of both human and non human resources of any establishment,

Non human resources like money, materials, machinery etc. This means that the manager or

group of managers provide leadership which results in the achievements of the stated

objectives of the organization or an establishment. E.g. Tate and Lyle, Kwara Polytechnic or

University of Ilorin a non profit organization like the Red Cross, Churches, Mosque just to

mention a few. From the foregoing definition we can see that management is very complex

and it is often best defined in dynamic functions or the ways it operates. Thus management is:

1. All human efforts to increase human efficiency in an organization.

2. The techniques of effective utilization of men and material resources to obtain the

desired results.

3. The process and agency which directs and guides the operations of any organization.

4. Group of managers.

5. Getting things done through other people.

6. To forecast and plan, to organize, command coordinate, control and to make

decisions.

7. A social process that entails responsibilities for the effective/efficient planning

regulation of the operations of an enterprise.

Management predates human existence. God himself started the concepts, principles and

practice of managements. However opinions vary with the historian on the subject matter of

history and the development of management. Management from the old French word

“management” refers to the “act of conducting, directing”. Also from the Latin word “Manu

agree” is “to lead by hand”. Management therefore characterizes the process of leading, and

directing all or part of an organization, often a business, through the deployment and

manipulation of resources such as human, financial, material & intellectual. One can also

think of management functionally, as the action of measuring a quantity on a regular basis

and of adjusting some initial plan and as the actions taken to reach one’s intended goal. This

applies even in situations where planning may not have taken place. Situational management

may therefore proceed and sometimes subjoin purposive management.

17

2.01 19th Century

Modern management as a discipline began as an offshoot of economics in the 19th century.

Classical economist such as Adam Smith and John Stuart mill provided a theoretical

background to resource allocation, production and pricing issues. About the same time,

innovators like Eili Whitney, James watt and Matthew soulton developed technical

production elements such as standardization, quality control procedures, cost accounting,

interchangeability of parts and work planning.

By the middle of the 19th century, marginal economist Alfred Marshall and Leon Walras

and others introduced a new layer of complexity to the theoretical understanding of

management. Joseph Wharton offered the first orfjklfkl in1881. By about 1900 we find

managers trying to place their theories on a thoroughly scientific basis. Examples include

Henry Towne’s science of mgt 1890s, Fredrick winshow Taylor’s scientific mgt (1911), frank

and Hillian Gilbreth’s applied motion study (1917) and Henry Haganttis Chart (1910).

2.02 20th Century

The first comprehensive theories of mgt appeared around 1920. People like Henri Fayol

and Alexandra Clurchi described the various branches of mgt and their inter-relationships. In

the early 20th century, people like Ordwatt Tead, Walter Scoth and J.moonery applied the

principle of psychology to management, while other writers Elton Mayo, Mary Parker Follet,

choster Bernard, max weber, rensis hekert and Chris arguing approached the phenomenon of

mgt from a sociological perspective. Peter Drucker wrote one of the corporations published in

1946. In the 1940s, Patrick Blackelt combined the statistical theories of Ronald fishor and

Throton C. fry with micro economic theory and save both to the science of operation research

to solving management problems in the areas of logistics and operations. But, towards the

end of the 20th century mgt came to consist of a number of separate branches which are, but

are not limited to the followings:

a) Operations and production mgt

b) Marketing mgt

c) Strategic management

d) Human Resources mgt.

2.10 SCIENTIFIC MANANGEMENT

Scientific management is the application of scientific methods to solving management

problems with the ultimate aim of increasing productivity. An American production engineer,

18

Frederick W. Taylor was a pioneer in this field and he is considered as the father of scientific

management.

The scientific methods are usually stated as:

a) Observation and collection of data

b) Analysis of the data collected

c) Classification of results

d) Development of hypothesis

e) Testing hypotheses through experiments

f) Application of the laws for predicting future circumstances.

The use of scientific methods to solve management problems was necessary after the

industrial revolution when industries grew in numbers and complexities. Also the system

used at that time was very crude, un-scientific and was incapable of solving management

problems. The prevalent problems at that time include proper selection of men, materials and

machines, what constitute a day job, maintaining of harmonious and cordial relationship

between the employer and workers. The methods employed. Was so inefficient that one of

the pioneers of scientific management, Dr. Jones made the following observations:

a) Current performance and the methods prescribed by craft and tradition were crude and

wasteful because the tools and apparatus used were not fitted to its purposes.

b) Workmen everywhere were performing task for which they were not fitted.

c) No one, workmen or manager, was aware of the time a given piece of work should

take and also how much work a “first class” should do in a day.

d) Managers were not aware of the impact or influence of delays and vacations on the

workers. As method before better methods of management had to be sought to take

care of things problems in the face of fierce competition and rivary that accompanied

industrial revolution.. Some of the pioneers in this field include Frederick W. Taylor,

Henry Gantt, and Frank Gilbreth.

2.11 Objectives of Scientific Management

The objectives of scientific management could be inferred from the testimony Taylor

made to the house (House of Representative) committee in 1912 in the U.S.A. it could be

summarized as follows:

a) To bring maximum prosperity for employers through increased productivity at

minimum costs.

b) To improve efficiency of the workers-through better training in the proper use of tools

implements.

19

c) To provide maximum prosperity to the worker by increase their wages which will

eventually enhance their live hood.

d) To maintain workers/employee’s relations by creating a harmonious industrial

environment as a consequent of a mental revolution.

e) To provide cheaper goods and services to the community.

2.12 Principles of scientific management

The principles of scientific management are contained in the famous Taylor’s

principles:

1) replacing rules of thumb with science

2) obtaining harmony in group action, rather than discord

3) achieving co-operation between management and workers as opposed to chaotic

individualism

4) Working for maximum output. rather than restricted output

5) Developing all workers to the fullest extent possible for mutual benefits-(labour and

management}.

2.13 Advantages of scientific management

1. Scientific management has changed the entire management technique which

ultimately increased efficiency.

2. It helps in proper and standard planning of each workers task and operation.

3. It helps in controlling

4. It helps in proper selection, training, placement and development of the workers

together with a provision of incentive wages and satisfactory service conditions.

5. It helps to create harmonious and cordial relationship between the labour and the

management.

6. It helps to raise the standard of living of the workers through increased output and

reduced cost per unit.

7. It helps to ensure technical efficiency through the standardization of tasks, tools,

equipments, raw materials etc.

8. It helps to remove the traditional antagonistic attitude stance of the employees and

employers towards each other and makes them understand that they have common

interests. Hence it brings mental revolution.

9. It brings more prosperity to both workers and employers i.e. more profit implies more

wages.

10. Cheaper and standard goods to the customers.

20

The following criticisms have been leveled against scientific management:

1. It reduces workers to innest object another mindless machines that has no feelings or

values.

2. Relationships between workers and workers are very impersonal.

3. It only encourages increased output and efficiency hence workers must completely

submit to the needs of machine.

4. The conditions under which workers work have ceased to exist.

5. Production and efficiency are now almost ready.

6. Workers received time and motion studies with hostility they feel that it will benefit

only the company while adversely affecting the workers.

7. Job simplification will lead to monotony, boredom, lack of challenge, and ultimately a

dehic introduction.

8. If proper and advance notice is not given to workers, workers can alter their normal

work rate thus influencing the results of observation adversely.

9. The one best way does not give enough room for individual differences in term of job

abilities and skills.

10. In adequate sampling, only a small number of the work force was sampled and only

best workers already performing the job were studied.

11. Work day and work week were inadequately sampled.

12. The simultaneous use of both hands in time and motion studies may not be feasible.

13. Later workers device better methods of doing things do it better thereby defeating the

idea of one best way of doing things.

2.14 Some Aspects of Scientific Management

Basically scientific management could be broadly divided into human and non-human

aspects. The human aspects include the following:

a) Selection of workers

b) Training

c) Time and motion analysis

d) Fatigue study

e) Wage incentive

f) Labour/management relations.

1) Selection of workers: Selection of workers is very important because productivity of

worker is directly related to the fitness of workers. If a worker is not fit to do a job he is not

going to be productive. Therefore the most suitable man for a job is Taylor’s first class man.

21

To get the most suitable man various procedures must be employed e.g. psychological test;

test to ensure both physical and mental fitness.

2) Training: Training is art of imparting the required knowledge and techniques to perform

certain duties. It is the corner stone of any efficient management. It helps to improve the

efficiency and skills of workers and also as a control device. It is required in the face of

outburst of technological changes and expansion of business.

3) Motion and time analysis is done by production standards on factory jobs. It has a two fold

process. The first process is the motion analysis to determine the best way of doing a

particular job by eliminating unnecessary movements. It includes breaking down the job into

its simplest elements, eliminating unnecessary motions and establishing a pattern for efficient

production.

Once the motion analysis is completed, the worker is trained in the new method. Then the

industrial engineer conducts a time study analysis, using a stop watch, to determine how

much time is required to perform the job under actual factory conditions. A number of

observations will be made to determine fairly the amount of time required for a particular job.

Allowances will however be made for variations in the worker’s work pattern as a result of

chances, or unusual circumstances e.g. workers fatigue, production delays etc. These factors

are incorporated into the average observed time to determine standard time for performing a

job and can judge what a normal pace is for doing that job.

4) Fatigue Study- It is a study conducted to determine weakness after hard work. When

workers perform some duties after sometime efficiency begin to diminish. Therefore

management (industrial engineers) conducted a study to determine the causes of fatigue.

Findings show that long hours of work, monotony of work, unhealthy working environment,

and constant strain under poor leadership are the contributing factors. Management has to pay

attention to these findings because fatigue decreases efficiency and productivity, it also

lowers quality of work and strains labors management relationships.

5) Wage Incentives- Wage incentives lends to motivate workers to improve production

output or productivity, efficiency and quality of work. If workers are motivated labour turns

over will also be reduced and good workers will be attracted.

i) Taylor introduced “Differential piece rate”. This involves the higher and the lower rates.

The higher rate for the fast and efficient worker while the lower rate was for the workers who

failed to perform the standard job within the standard time.

22

ii) Taskes and bonus system was another method of paying wages under scientific

management. It was introduced by Lawrence Gantts. The system guarantees a day wage

workers and bonus for any extra of the task bonus is attained. It is on a daily basis.

iii) Emersons introduced another system known as efficiency wage. Under this system

bonus is computed on a weekly and monthly basis.

6) Labour/Management relations- For any management to succeed there must be good

corporation and harmonious relationship between labour and the management team. Taylor

realized this and pointed out its importance. He said among other things that good

corporation between labour and management brings changes in the attitude of the workers

and the management and therefore brings about a mental revolution.

2.15 NON HUMAN ASPECTS

Non human aspects of scientific management include the following:

a) Tools and equipments

b) Machine speeding

c) Factory conditions

d) Materials

e) Functionalization

f) Planning room

1) Good tools- for good performance good tools and equipments are required. For

equipment to function effectively, it must be properly installed and maintained. These

scientific managers paid particular attention to the proper installation, maintenance

and accessibility of machines in the factory to enhance productivity and efficiency.

2) Machine Speeding-The speed of the machine is very important for good productivity

and efficiency. The speed should be standardized. When a standard speed is achieved

then it could be adjusted to the desired speed.

3) Factory Conditions-Good working environment is required for good productivity

and efficiency. The scientific managers realized this and therefore made adequate

provisions for proper ventilation colour, heating, cooling, lighting, drinking water,

rest or recreation as the case may be.

4) Material- Great importance is attached to the good supply of quality materials.

Researches were conducted to discover or invent new raw materials that will enhance

productivity and product quality.

5) Functionalization- Scientific management encourages division of labour. Delegation

of authority rest solely on functions and or techniques. Therefore each manager or

23

worker is assigned a job in which he is best fitted. This method tends to encourage

professionalism. It helps management to get detailed information and expert advice.

To achieve better productivity, Taylor suggested the “Functional” type of

organizational in place of line and staff form of organization. He further suggested

functional foreman to replace a single foreman who serve as the sole administrative

figure. It tends to relieve the manager and the foreman of unnecessary burden.

6) Planning Room-Taylor suggested separate planning room whereby specially trained

planners will do planning jobs. According to Taylor, order of work, preparation of

instruction cards, compilation of time study records and machine speed records,

entering of costs records etc. are to be done in the planning room.

Scientific management focuses on worker and machine relationships. Organizational

productivity can be increased by increasing the efficiency of production processes. The

efficiency perspective is concerned with creating jobs that economize on time, human energy,

and other productive resources. Jobs are designed so that each worker has a specified, well-

controlled task that can be performed as instructed. Specific procedures and methods for each

must be followed with no exceptions.

2.20 FREDERICK .W. TAYLOR (1856-1917)

Frederick Winslow Taylor was the “father” of the scientific

management “movement” “He believed that management should be based on well

recognized, clearly defined and fixed principles, instead of lazy ideas”. Taylor was born in

Philadelphia on March 20 1856. He was to study at Harvard University but he had to shelve

the idea because of the condition of his eye sight.

In 1878 he went to Midvale steel company as a machine shop laborer. As a result of his

hard work he had rapid promotions. He was a shop clerk, machinist, gang boss, foreman,

maintenance foreman, head of the chew office and chief engineer.

He studied at night and earned degree in mechanical engineering from Steven’s

Institute of Technology in1883. His purpose was to maximize efficiency and productivity.

When he discovered he could not arouse enthusiasm in the workers he suggested

money/wage incentive should be given to workers who are efficient. This he thought would

benefit both the workers and the employers. According to him workers and employers should

not argue on how profit should be divided but both workers should work together on how

greater efficiency and productivity could be achieved so that there will be more profit to

24

share. After careful studies he discovered that low productivity in the industry was, according

to him as a result of:

a) Unclear concept of managerial responsibility

b) Lack of measured standard for defining tasks

c) Widespread inefficiency of labour and “Systematic soldiering”.

To improve efficiency and productivity he made the following recommendation

which was later christened as Taylor’s principles.

a) The rule of thumb must be replaced with science he believed there is a science for

every work therefore management must discover it.

b) The scientific selection and progressive development of the workers training teaching,

development of workers should be the responsibility of the management and to be

scientifically done too.

c) Achieving co-operation between workers and the management.

d) There should be division of work between the workers and the management-

management to take over all work for which they are better fitted than the workmen.

These principles are designed enhance the productivity and efficiency of workers in

an organization and they form the basic principles of scientific management.

a) Time study principles: Taylor recommended accurate measurement of all productive

efforts to determine a standard time for all work done in the factory. He used a stop watch to

achieve these objectives

b) Piece-rate principles: There should be a direct relationship between wages and output.

The rates should be based on standards to be determined by time study analysis in addition a

worker should be given the job in which he is best fitted for. Differential piece rates was

recommended for rewarding the good workers-higher rates for fast and efficient workers and

lower rates for slow workers who are unable to attain the targets.

c) Separation of planning from performance: Planning should be done by management and

good atmosphere for performing the planned job to be provided too planning should be based

on the time of study and other data that are scientifically collected include standard tools,

implements and methods.

d) Scientific methods of work management should scientifically define the methods of doing

a job and not the workers.

e) The principle of managerial control. Managers are to be trained and taught how to apply

scientific management for principles in the art of controlling.

25

f) Functional Management Principles: Taylor recommended that industrial organization

should be designed in such a way that it best solved their problems and the strict application

of the live and military principle should be reconsidered.

g) The Worker Job: Taylor said it is the responsibility of the management to determine what

constitute a day’s job. This could be done by conducting a time and motion analysis by the

management. The working man (Labour union) According to Taylor, if his scientific

management principles are implemented there will not be any need for labour union. It is said

however note that some of the efficiency Experts misused his principles by paying workers

less and therefore his principles were considered anti union. He was not against unions.

2.30 HENRY LAWRENCE GANTT 1861-1919

Henry Gantt was one of the contemporaries of Taylor. He too was a mechanical engineer

and he joined Taylor at Midvale Steel Company in1887.

He “married” some Taylor’s ideas and did much consulting work on scientific selection of

workers and the development of incentive homes systems. He had a better understanding than

Taylor of workers psychology. This was manifested in the importance he attached to the

morale boosting and the use of no financial rewards to achieve it. According to, Gantt,

management should provide favorable environment which will make workers

psychologically fit for his job.

Taylor laid emphasis on methods-analysis and organization of work, while Gantt

emphasized men. His concept of motivation is very much the same as one perceive it today.

Gantt is best remembered for his development of his charts-a graphic method of depicting

plans and making it possible for managers to have better control. “He emphasized time and

cost in planning and controlling work. His famous “Gantt Chart is in wide use today and he

was the forerunner of such modern techniques PERTH. Program Evaluation and Review

Technique.

He is also remembered for his Task and Bonus system of wage payment which was based

on Taylor’s piece rate system except that it was more flexible. There is fixed rate of payment

for every worker and a bonus is an extra rewards for the worker who complete their jobs. His

bonus system provide bonus not only for the workers but for the foreman too. This method

too relied solely on the outcome of time and motion study analysis.

26

2.40 HENRI FAYOL (1841-1925)

Fayol is considered as the father of modern management theory. He was a French

Engineer by profession. He is popularly known as the Universalist because he believed there

should be a single administrative science whose principles could be used in all administrative

cases in any organization. According to him, managers need nothing more than the principles

and that at upper level of management, managers depend on less and less on technical

knowledge of what he is managing. This means the need for technical knowledge decreases

with a rise in the management hierarchy. This should not be misunderstood however because

he believed that even at the top, top managers could not depend on administrative skills

alone. In fact, in discussing the qualities heeded by top management, he gave administrative

ability a weight of only 50% in the case of a very large firm, only 25% in the case of small

firm top manager.

Fayol found that activities of an industrial undertaking could be broadly divided into six

groups. Activities and undertaking:

1. Technical (production-manufacture)

2. Commercial (buying, selling, exchange)

3. Financial (search for optimum use of capita)

4. Security (protection of prosperity and persons)

5. Accounting(including statistics, stock taking, balance sheet (costs) )

6. Managerial (planning, organization, command, coordination and control)

He pointed out that these activities are present in businesses of every size. In his book he

spent much time on the analysis on the sixth since he believed that the first five were well

known. His concept of universality of management principles gives rooms for flexibility, in

application. According to him, to apply the same principle twice in identical conditions,

allowance must be given for different changing circumstances for men and other variables.

Fayol listed fourteen (principles) based on his experience. The principles are summarized as

follows:

1. Division of work: The economist considers it necessary for specialization to enhance

efficiency. Fayol applied it to all kinds of work, managerial as well as technical.

2. Authority and Responsibility: Fayol distinguished between a manager’s official

authority (deriving from his office) and personal authority (deriving from his

experience, moral worth, intelligence e.t.c.) Authority should commensurate with

responsibility; this means the holder of an office should have adequate authority to

carry out all the responsibilities assigned to him. He also suggested that “generally

27

speaking, responsibility is feared as much as authority is sought after, and fear of

responsibility paralyses much initiative and destroys many good qualities.

3. Discipline: He said that discipline requires good superiors at all levels since discipline

is respect for agreements which are directed at achieving obedience, application,

energy and the outward marks of respect. Therefore the state of discipline of any

group of people depends on the quality of its leaders.

4. Unity of Command: This means of or any action subordinate should receive orders

from superior only. He saw dual command as a disease whether it is caused by

imperfect demarcation between departments or by a superior giving order to an

employee without going via the intermediate superior.

5. Unit of direction: There should be one and one plan for each activity. The relates to

the organization of the “body corporate and not the personnel.

6. The interest of one employee or group of employees should not prevail over that of

the general interest of the organization.

7. Remuneration: Remuneration and methods of payment should be fair, satisfying

both employer and employee alike.

8. Centralization: This refers to the degree to which authority is concentrated or

dispersed. Individual circumstances should dictate the extent of it.

9. Scalar Chain: This describe the chain of superiors from the lowest to highest rank.

Formal communication is up and down the lines of authority.

10. Order: Fayol believed there should be a place for everything and everything in its

place.

11. Equity: There should be fair play.

12. Stability of tenure of personnel: He discovered that unnecessary turnover to both the

cause and effect of bad management “It has often been recorded that a mediocre

manager who stays infinitely preferable to outstanding managers who merely come

and go.

13. Initiative: “It is essential to encourage and develop this capacity to the fullest”.

14. Esprit de corps: Personnel must not be split up. Verbal communication is preferable

to written communication, which is frequently abused, causing friction between

departments.” In union there is strength”. Fayol considered the main elements of

management to be planning, organizing, commanding, coordinating and controlling.

28

2.50 FRANK GILBRETH (1868-1924)

Frank and his wife Lillian Gilbreth were contemporary of Taylor. They both supported

and developed Taylor’s ideas. Frank gave up going to the university to become bricklayer so

as to make quick money. Like Taylor, he received quick promotions. He rose (became) the

chief superintendent of a building construction within ten years. Later he became a building

contractor himself. He became interested in wasted motions in work. Later his contracting

firm became a consulting firm-consulting on how to improve human productivity. Lillian

Gilbreth worked very closely with her husband; she had doctoral degree in industrial

psychology in1915. She was known as first” lady of management”. Lillian was interested in

the human aspect of work while her husband’s interest was in efficiency-searching for the

one best way of doing a job.

They discovered that job dissatisfaction has its origin not in the monotony of job but

management’s lack of interest in workers.

2.51 The One Best Way:

Gilbreth’s interest in the one best way of doing a job Waslater christened as a system of

short cut of laying bricks. The one best way was the way which involved the fewest motions

performed in an area that is most comfortable and accessible too. By applying his methods in

bricklaying, the numbers of motions were reduced thus increasing efficiency and

productivity.

He believed motion study could be used in all work including production, research labs,

government and civil offices etc. According to him improper arrangement of men and

materials are responsible for wasteful motions and efforts which caused delay and has

negative effect on worker’s morale.

2.53 Time Study

He developed a new type of time study that was more accurate than Taylor’s. He used

speed clock instead of stop watch used by Taylor. He also took motion pictures in three

dimensions to find out the exact time.

2.54 Three-position Plan of Promotion

To attract desirable applicants, to fill a position, he developed a plan known as three

position plan of promotion. According to him, each worker should be seen as occupying three

positions at the same time.

1) His previous job- The job he held before he got promotion to his present job.

29

2) His present job- The position he is occupying now.

3) The next job- The next higher job he would like to be promoted to. The implications

of this plan are that three records must be kept.

a) Individual record

b) Collective records and

c) Records of personnel in charge of promotion

Gibreth work as similar to Taylor’s but was independent of his. His emphasis was on

motion study and less on time study and financial incentives. He believed there was “one

best way” of doing a job and that could be discovered by time study. His major

contribution was his regards for human elements- Taylor’s short comings.

2.60 ELTON MAYO (1880-1949)

Elton Mayo was a professor of industrial research psychology at the Graduate school of

Business, Harvard University between 1927&1947 in the U.S.A. He was an Australian by

birth but an American by naturalization. Between 1927 and 1932 he and Fritz Roethlisberger

made a historic study at the Hawthorne plant of Western Electric Company. In the

experiments he tries to find out the effect of changes in certain variables (working conditions)

on the productivity of workers. The variables were lighting, heating; rest periods, incentive

pay system e.t.c. In the Hawthorne experiments he used five girls as “guinea pigs”. They tried

changing the above variables but noticed that the changes in the variables did not seem to

explain changes in output productivity were increasing. They then came together conclusion

that other factors were responsible. They suggested that the relation among the group

members between the group members and the supervisors were the critical variables-i.e.

social attitudes and relationships of work groups. According to them productivity was

increasing when illumination was changing because the test group began to be noticed and

were feeling important sense of belong. “This phenomenon arising basically from people

being” noticed” has been known as the Hawthorne effect. “Humans are social. The following

conclusions could be drawn from the Hawthorne experiments:

1. That the level of productivity is directly related to the workers attitude or morale.

2. That the worker should be allowed to have inputs in the changes to be made so as to

get his full co-operation and understanding- sense of belonging is more important than

any other thing else.

30

3. That the influence of group on individual performance is very great. It must be

emphasized that all the variables reinforced each other.

Unlike Taylor, Mayo was more concerned about the human aspects of productivity. He

believed that economic motive on which Taylor much emphasized, was not as important as

the emotional and non-logical attitudes and sentiments.

They said” Attitudes to people, as people, may be more important than such factors as rest

periods, benefits, money e.t.c. People are not merely instruments.”

2.70 The role of Civil Engineer in National Development

1. Abundant employment

2. Good food.

3. Moderate houses.

4. Good health.

5. Drinkable water.

6. Sound education.

7. Regular electricity.

8. Good roads.

9. Extensive rail transportation.

10. New water ways transportation.

11. Safe flight facilities.

12. Security of lives and properties. (national defense plans execution)

31

WEEK THREE 3.0 MANAGEMENT FUNCTIONS (PROCESSES)

3.01 DEFINITION OF MANAGEMENT

Management is a process of getting things done through other people, in other words

management are individuals or group of individuals who have authority and responsibility in

getting things done in an organization.

Henri Fayol (1919) defines management as to forecast duet plan, to command and organize,

and to coordinate and control. Stonel and Wankel (1988) viewed management as a process of

planning, organizing, leading and controlling the efforts of organization members and of

using all other organizational resources to achieve stated organizational seals. Management is

therefore a system that consist of interdependent and interacting parts that forms a unified

whole. It consists of the:

a) Input- Human resources

- Machines

- Finance/capital - Materials

b) Process – Planning, organizing, staffing, influencing, leading, directing, motivation,

communication, controlling and coordination.

c) Output- Achievement of objectives, production, marketing, accounting & finance,

Engineering, Administration, purchasing and supply and quality assurance/control.

However, the operations of each subsystem depend on each other and determine the overall

success of the organization. These subsystems must be properly coordinated so as to achieve

organizational objectives.

3.10 MANAGEMENT FUNCTIONS

Management objectives are achieved when its functions are carried out. The tenets of

management rest squarely on its concomitant function. Its functions include the followings.

1) Planning

2) Organizing

3) Coordinating

4) Controlling

5) Budgeting

6) Motivating

7) Staff and

8) Effective communication

32

3.11 PLANNING

Planning simply refers to the process of determining corporate objectives and how they

will be accomplished; In other words it is the process of setting goals and objectives for an

organization and determines how to achieve such goals and objectives. It is anticipating

decision in designing an environment for the effective performance of individual working

together in groups. However, for effective planning in an organization certain process should

be followed:

1) Scan the environment: - The organization should be aware of the opportunities and

threats in the environment, the consumer needs, the resources available, the

management size, the competition and the scio-economic and political factor and also

the strengths and weakness of the company.

2) Set objectives and goals in relation to the mission purpose of the organization. This

should answer questions such as: “where are we in the organization”, where do we

want to be” and when?

3) Selecting the best alternatives

4) Implement the plan, monitor it and develop feedback mechanism for organizational

effectiveness, planning should be seen as the foundation of managerial functions,

Therefore careful attention should be taken both in the process and implementation of

plans.

3.12 ORGANISING

Organizing is concerned with activity and authority relationship of an enterprise. It is a

management process which has as its outcome the resultant organizational structure.

Organizing therefore is simply the grouping of activities necessary to attain the enterprise

objectives and the assignment of each group to a manager with necessary authority to

supervise it. Managers who are tasked to perform this function and creature and intelligent

and possess adequate information about the enterprise objectives, polices, Procedures,

programs, rules and other available resources. The steps to organizing are:

1) Review plans

2) List task

3) Group tasks into jobs

4) Group jobs

5) Assign work

6) Delegate authority

3.13 CONTROLLING

33

Controlling is a vital management function in that it ties the subordinates performance

to the enterprise plans. No matter how effective the execution of other management

functions, control is still needed to ensure that the enterprise objectives are accomplished

according to plans.

In essence, controlling is simply the process of comparing performance with standards and

correction of any observed deviations, It is directly related to planning. The controlling

process that plans are being implemented properly. In the reality controlling involves the

process through which standards for performance of people and processes are set,

communicated and applied. Control facilitates delegating activities to employees, since

supervisors are ultimately held accountable for their employee’s performance, timely

feedback on employee activity is necessary.

3.14 STAFFING

Staffing as a management function is a general term used to describe activities is

getting people into the organization as employees. It involves job analysis, man power

planning, recruitment, selection, placement and the socialization process in an organization.

This is done by identifying workforce requirements, knowing the number of staff available,

recruiting, placing, planning the carrier, comperisation and training or otherwise developing

both new candidates and current job holders on how to accomplish their tasks effectively and

efficiently.

3.15 MOTIVATION

It involves finding incentives which satisfy workers needs and increase workers

commitment and effort towards the goals and objectives of the organization. In other words,

it involves a process of encouraging or inducing employees or perhaps a way of giving a

person a reason for doing the things you want him to do.

3.20EFFECTIVE COMMUNICATION

Communication establishes relationships and makes organizing possible. Every

message has a purpose or objective. In essence, in any organizational context, messages

typically have a definite objective to motivate, to inform, to teach, to persuade, entertain, and

to inspire people the comprised organization. Effective communication in the organization

centers on well defined objectives that support the organization’s goal and mission. In other

words, the use of modern information technology enhances the effectiveness and efficiency

of any organization most especially day to day running of the establish due to an effective

communication mechanism put in place at a particular time in a specific area.

34

35

WEEK FOUR 4.0 Designing an Organization

Every organization is made up of human and physical resources. These resources are

brought together in order to accomplish a predetermined goal. In order to accomplish these

objectives, tasks must be identified, the tools and technology required must be provided and a

structure of relationships must be identified. It is the function of management to determine

the best structure that will optimize the utilization of resources. Management organizes

these resources. Thus organization is a means of achieving the best result from concerted

effort. Organization deals with people that determine the type of people required and required

and their relationships. Thus the type of personnel and structure required in a hospital is

different from the personnel and structure required in a weaving enterprise or a university.

4.01 Meaning of Organization

An organization can be seen as an entity. This is true of all business enterprises,

churches, hospitals, or clubs. It can be seen as a process of coordinating individual efforts to

accomplish a common objective, An organization is a group of people bound together to

provide unity of action for the achievements of a pre-determined objective. All management

teorists-Fayol, Follet, e.t.c recognize this important management function. Organization is

very fundamental to human nature. Man is a social animal and shares relationship with his

neighbors. The subject of organization is central to sociology, psychology and even

anthropology.

4.10 Kinds of Organization

Organizations can be classified into two broad headings such as:

(a) Formal and

(b) Informal organizations.

4.11 Formal and Informal Organizations

The later is human interaction that occurs simultaneously and naturally without overt

influence. Formal Organizations can be seen as a direct opposite of informal organization. It

is a planned pattern of group behavior designed to achieve an objective.

Most relationships found in many business enterprises are formal. The main reasons for

formal organizations are:

1. to establish efficient and logical patterns of interrelationships among members of the

group.

36

2. to secure advantages of specialization or division of labour whereby the optimum

utilization of talents can be realized.

3. to coordinate activities of the of the component parts in order to facilitate the

realization of the goals of the organization.

In Nigeria, the problem of formal organization is not so acute because of the nature of

Nigerian business. As an organization grows, the component parts become more complex, the

technology changes and requires special expertise and consequently, more attention. Small

enterprises do not require the same magnitude of tasks as large ones and are therefore easier

to design.

4.20 Organization Charts

An organizational chart is a visual device that shows the various departments and how

they relate to one another. The organization chart helps the employees, the board of directors

and stockholders to see at a glance, the division of responsibility and lines of authority. One

of the major advantages of an organization chart is that it helps in studying how to modify or

improve the relationship and areas of responsibilities within the organizational structure. An

organization can operate without a formal, drawn organization chart, but the presence of the

chart gives evidence of a thoughtful planned structure. Nevertheless, it shows the existence of

a workable structure. Never the less, it shows the existence of certain positions identified by

boxes and line of authority shown by solid straight lines connection, The figure below shows

an example of an organization chart.

4.21 Organization chart

Chief Resident Engineer

Agent

Asst. Chief Measurement Engr.

Fin

Asst. Chief Water Engineer

Asst. Chief Engineer (Elect / Mech)

Manager (Fin. And Admin.)

Quantity surveyor

Engineers

37

4.30 Organization Structure

Sound Organization structure involves dividing activities into departments,

divisions, Units sub-units, defining relationships between the heads and members that make

up the units. A good structure;

a) identifies the operating departments (sales department, Production department, and

finance department).

b) isolates the service department (Personnel, research)

c) places emphasis on balancing the structure.

d) Shows the role of committees in the organization.

One of the major problems confronting management is to decide the organizational

structure to be adopted. Important questions relating to duties and role of each department

and line executive have to be clearly defined. A decision has to be made whether the

organization is to be decentralized or centralized and the type of staff required for each task

has to be determined. As Simon succinctly summarized it, the important features of an

organization to be designed include:

a) Division into sections and units, number of levels, locations of decision-making

authority, distribution of and access to information, physical layout of building, type

of people recruited, what behaviors are rewarded and so on.

In the process of designing an organization, managers invent, develop and analyze

alternative forms for combining these elements.

38

A good organizational design is one that leads to the attainment of organizational

objectives. A good organizational design is not one that is fixed and will never require a

change. The system is subjected to change when the environment in which it operates

changes or when the company is expanding its operations or changing its objectives or during

the process of re-organization. A good organization is judged by its economic performance,

ability to survive in a dynamic environment and the growth and satisfaction of the members.

4.40 Forms of organization

4.41 Line organization: In a typical line organization, authority flows in a straight line

from Board of Directors to the Managing Director and to lower management levels. Every

line executive has identified responsibilities and authority assigned to him and has the

supporting staff to execute the functions. A manager with line authority is answerable for the

performance of his subordinates. Those employees with line function are responsible for the

immediate attainment of organization’s objective. The flow of authority and responsibility is

usually straight or direct and accountability is easily established.

The advantages of Line Organization.

1. This structure is simple and easily understandable by all, accountability is easily

established. Conflict of authority is reduced to a minimum.

2. It lends itself to quick decision-making. Decision making is vested in one person who is

in charge of the department.

3. Expenses related to overhead are reduced to a minimum as the role of executive

specialists is eliminated.

4.42Line and Staff Organization.

This form of structure resembles the line structure only those specialists are included in the

organizational arrangements. Decisions are made by line executives with the advice of staff

executives. Staff executives are experts in their fields – (accountants, lawyers, personnel

specialists, engineers etc.) they advise the line executives who are directly responsible for the

immediate attainment of the organizational goals. Figure 5.2 shows the line and staff

structure.

Line and Staff Organization Structure

Director General

Manager Production

Manager Finance

Manager marketing

39

In this chart, the solid lines represent the flow of authority and dashed or broken lines

indicate a staff or advisory relationship.

The advertising manager can advise salesmen but he has no direct control over them.

Authority relationships are discussed in full below.

Line and staff structure is best used when the organization is relatively large and serving a

big market.

4.5 Authority Relationship

4.51 Line Authority: As pointed out, Line authority Connotes “command” relationship. This

is the authority that makes one expect obedience from subordinates. Line authority has been

described as the chain of command as it flows from the stockholders to the Board of

Directors, to Managing Director all the way to the operative employees. As Fox observed,

“Line position in an organization are those concerned directly with the creation and

distribution are those concerned directly with the creation and distribution of salable utilities

or with the management of such activity.”

4.52 Staff Authority: This position is advisory in nature. Gene rally, staff executives are

specialists who study a problem, identify the alternatives and make recommendations to the

chief executive for decision. He advises, and to advise is not to decide-only the line executive

is vested with that authority unless this power is delegated to him.

4.53Functional Authority: This process allows a staff executive (engineers, Lawyers,

accountants, advertising managers) to make decisions and implement them within clearly

defined guidelines. This process reduces the work load of line executive by taking advantage

of the expertise of the staff executive. The staff authority aims at supplementing the activities

of line authority. This process helps to reduce the usual conflict between line and staff

executives.

Plant Supervisor

Chief Engineer

Controller Treasurer Salesmen

Field Sales

Manager

Advertising Manager

40

It should be observed that line authority is the back-bone of hierarchy; staff and functional

authority only supplement the line. In Nigeria, especially in small and medium organizations,

a person serves as line, staff and functional personnel at the same time. A personnel executive

advises the production manager or personnel matters, supervise his own department and sets

out policy guidelines on personnel matters.

4.60 Authority and Responsibility

Authority as used in the text is the right to act or decide. It describes the relationship

between and among people or groups. A person has authority if he has the right to command

and expect obedience from the subordinate.

No organization could survive if authority had not been vested in some people. In fact, an

organization is nothing but a structure of authority flows from the top downward. In

designing an organization, the authority relationship is clearly defined. It is the responsibility

of those in whom authority is vested to coordinate the activities of the organization in order to

accomplish organizational goals.

Organizational authority is vested in the position not on individuals. The authority is vested

in the position not on individuals. The authority is given to an employee because he needs the

degree of authority in order to achieve a given level of productivity or sales. When the

individual resigns, the authority is inherited by another employee who occupies the position.

In this case we speak of the authority of the manager, the powers of the authority of the

manager, the powers of the president or the governor.

4.70 Power and Influence

At this juncture, it is necessary to distinguish between power and influence in order to

contrast them with authority. Power is the ability an individual has to compel another to do

something against his will despite any resistance. A man who holds a business man at

gunpoint demanding that the businessman should surrender his goods has power to take

possession of the goods. Power is evident in a situation when A has control over B or can

force B to do something he does not want to do despite resistance.

Influence, unlike authority, is not vested in an individual. A has influence over B if he can

modify or affect B’s behavior. Thus influence is a very moderate form of power. A person

influences his friend because of the rapport they have established over the years. One who

influences, uses persuasion and suggestion to achieve a desired end. Influence takes place in

all interpersonal relationships. Unlike power which implies a fear of punishment, harm or

loss of status, influence does not.

41

In an organization, the interpersonal relationship sometimes dictates the use of authority,

power or influence. A supervisor can also influence an employee to accept position.

Authority is a source of influence and a potential source of power.

A physician may persuade a patient to submit himself to operation. He has in this instance

knowledge-based influence just as personal characteristics such as self-confidence, honesty,

appearance, or dynamism can give one charisma based influence. In Nigeria a person’s

appearance influences the receptionist to decide whether the visitor will see a manager

without waiting or not. So it is in service establishments such as the post-office, banks, and

even restaurants and hotels.

4.80 Sources of Authority

As pointed out, an organizational authority is a right to act, to punish and to reward. A

person who possesses this authority usually has equal responsibility to match. Authority is

vested in a position and the position becomes the source of authority for who ever steps into

it.

4.81 Institutional Source

It is often said that authority is derived from the ownership of property. This is the case

because, in Nigeria, the constitution permits the ownership of private property and its

management. Once an entrepreneur has been given a license to operate a business, ha has

authority from the country to own and manage the enterprise. This authority he can delegate

to his agents or subordinates as he deems fit. Any person who accepts employment with the

organization is subject to the authority of the owner or his representatives.

In organizations people often refer to responsibility being delegated instead of authority and

responsibility go hand-in-glove. One cannot operate without the other. An entrepreneur

cannot operate his labour he owes them a reasonable wage and he has authority to enforce

compliance for the rules and regulations that govern interpersonal relationships. The origin of

authority, whether in economic institution or in social institution where private property is

non-existent may be traced to the elements of basic group behavior. As these elements

change, the institution must change.

This authority transmitted from the basic social institution to entrepreneurs and managers is

aptly called formal authority. This formal authority so granted could be called institutional or

societal.

4.82 Subordinate-Acceptance source.

The acceptance of authority theory postulates that the source of managerial authority

emanates from the subordinate acceptance of the authority that the manager holds over them.

42

One of the great authorities in the field of management, Chester I. Barnard made the

following observation on the acceptance of theory:

If a directive communication is accepted by one to whom it is

addressed, its authority for him is confirmed or established. It is admitted

as the basis of action. Disobedience of such a communication is a denial

of its authority for him. Therefore, under this definition the decision as

to whether an order has authority or not lies with the person to whom it

is addressed, and does not reside in “person of authority” or those who

issue these orders.

The acceptance theory places great emphasis on subordinate acceptance of the

authority of the superior. Generally a subordinate will recognize and accept his

supervisor’s authority if he perceives that his directives are in keeping with

organizational purposes and will lead to the attainment of his own objectives. The

authority, an individual has to effect compliance could be reinforced by other means

such as persuasion, coercion, use of power, economic or special sanctions. A

manager does not depend on acceptance for the execution of his functions; if he did,

there would be conflicts and organizational objectives would suffer.

The basic error of the acceptance theorists consists not only in conceiving

authority, without sanctions, but also in overlooking the powerful effect of social

institutions, which confer powers that supersede individual desires.

The effectiveness of one’s authority could be influenced by acceptance but may

not necessarily be nullified by the accepting agent’s attitude. Acceptance theory

appears to place emphasis on leadership which deals with the ability to influence

others’ behavior in order to achieve a given objective. Management has authority

and if this authority is not fully accepted by subordinates, it could use power or

sanctions to secure compliance. The acceptance of employment in an organization

implies the acceptance of authority in the establishment.

The acceptance of authority is enhanced by the personal qualities of the manager,

such as technical competence, supportive behavior and dynamism. These qualities

of leadership are fundamental to the effectiveness of management and not

necessarily in the source of authority.

4.90 Limits of Authority

Formal authority is very fundamental to the attainment of organizational objectives. All

managers who occupy positions of responsibility are vested with it. Effective utilization of

43

authority promotes organizational harmony and consequently the realization of intended

goals. Certain factors limit the amount of authority a particular executive possesses. These

factors include one’s level in the organization, superior authority and subordinate acceptance.

4.91 Level in the Organization

As discussed previously, authority is delegated from top to bottom. The higher a manager

is within the organizational hierarchy, the more authority he possesses. The managing

director has more authority than deputy and the deputy possesses more authority than the

managers and supervisors. The higher the functions a manager has, the more the authority

that is vested in him for the effective execution of these functions.

4.92 Superior Authority

In this authority, an executive has his influence by the authority of those above him. A

superior authority influences the authority delegated to lower executives in any organization.

The production manager’s authority to produce is influenced by the organization’s

established policies and producers. He cannot recruit employees in order to achieve

production quota without following the guidelines for recruitments. He could also be asked

by a superior authority to stop production until certain conditions are fulfilled.

Closely allied to the influence of the superior authority that limits his authority, is

overlapping authority. Where authority overlaps, authority is held in abeyance until it is

resolved. Situations arise in an organization where two executives engage in a dispute as to

who has the authority to approve an expenditure, to authorize the purchase of equipment or to

hire employees. A labour union on strike has the ability to frustrate the efforts of management

to function effectively. It has to be noted that that authority is not cancelled by power conflict

between executives, management or labour unions, or government and entrepreneurs. When

conflicts arise, authority is held in abeyance until the conflict is resolved.

4.93 Subordinate Acceptance

The acceptance of authority by subordinates helps in the expeditious attainment of desired

goals. Failure to accept one’s authority produces the opposite effect. Refusal to accept one’s

authority does not cancel one’s authority; it only reduces one’s effectiveness in the given

situation. The degree to which the manager is rendered ineffective depends on the amount of

power he has to evoke penalties to effect compliance. Ability to evoke punishment and to

reward is implicit in all formal authority.

A good executive does not have to punish the entire item but when the need arises, it is

reassuring to know that one could exact compliance. For conditions must be met before a

message is accepted as authoritative:

44

1. It must be understood by the recipient.

2. It must be consistent with the purpose of the organization.

3. It is not incompatible with the personal interests of the recipient.

4. It is within the mental and physical abilities of the recipient.

Many experts have stressed the fact that the acceptance theory could be misleading as the

manager could be tempted to manipulate the situation in order to obtain acceptance from

subordinates.

Other factors that limit effectiveness of authority include technological constraints,

economic limitations, social limitations and organizational constraints.

Responsibility

People in authority are answerable to somebody for their use of authority. This is

responsibility. Responsibility implies obligation. A person to whom one delegates authority is

obliged to execute satisfactorily the assigned duty. Responsibility originates from a superior –

subordinate relationship. A subordinate must answer to his boss for the use of formal

authority just as a man answers to his friends for informal authority. In organizations,

responsibility is shared. When a manager authorizes an employee to execute a task, the

obligation created by this delegation from the supervisor to subordinate is shared.

45

WEEK FIVE 5.0 PARTIES TO CIVIL ENGINEERING CONTRACTS AND THEI R

NTER-RELATIONSHIPS

The maim parties to civil engineering contracts, their roles, responsilvlihes

And interrelationships are as described below:

5.01 Client

The client may be the sponsor (financier), promoter or employer of other parties such

as consultant or contractor for the execution of the project. He may be someone appointed by

the sponsor or promoter to employ or engage others for project execution. If the client is not

the sponsor, he becomes the first link in the reporting chain, who reports directly to the

project owner or sponsor and carries the responsibility for all major project decisions.

The client undertake, to fulfill his own side of the consultancy or contract agreement

just as the consultant and contractor are expected to do in the consultancy or contract

agreement format known as form of agreement. The client owes it a duty to ensure steady

cash flow to provide the enabling environment for speedy and smooth execution of the

project.

5.02 Consultant

He is a specialist or an expert entrusted with the task of providing necessary

professional and technical services in the areas of planning, designing, financial estimation

and evaluation, project implantation, management and maintenance. He prepares the tender

document as the basis for appointment of contractors and sub-contractors or suppliers to

execute the job. He supervises, appraises and evaluates the works of the contractor and raises

appropriate certificates based on the budget approved by the client; and makes

recommendation to the client about the progress of work and payments to be made to the

contractor both in terms of the original content of the BOQ on the date of the tender and the

46

fluctuation and variation claims verified and approved by the consultant. Where the

consultant indicts the contractor for breach of contract, he can prescribe appropriate sanctions

in accordance with the conditions of contract.

5.03 Contractor

The contractor is a person or a company appointed by the client, usually in

conjunction with the client’s consultant to implement the requirements of a project. The

contractor may be appointed through open tendering, selective tendering or negotiated tender.

The consultant / contractor may appoint the sub-contractors through the project manager. The

contractor’s other functions include:

a) Mobilization to site in a formal handing over exercise jointly by the practices

involved.

b) Prepare a workable and realistic work Programme at the instant of the consultant.

c) Delivers and maintains plants and materials on site.

d) Constructs site office and provides utility services on site.

e) Makes himself available at any appointed time for site visits, inspections and

meetings.

f) Sends written observation to the consultant on notable differences between the

contract drawings and BOQ.

g) Provides insurance cover to workers and ensures safety of persons and security of

the site.

5.10 Contract Documents

A contact should always specify what documents, letters, specifications e.t.c. are to be

regarded as the ‘contract documents’, and these normally define the contract. If however in a

court of law, the contract document themselves leave uncertainty as to the true intentions of

the parties at the time of signing the contract. Other letters and documents might. Subject to

47

the rules of evidence, be introduced by either party as evidence, of such intentions. In the sort

of contract we are considering the contract documents will usually comprise some or all of

the following:

- A statement of the scope of the contact

- Data (e.g. site conditions, climate) affecting the execution of the works.

-Bills of Quantities (especially in civil engineering and building construction); Priced

schedules or Plant (in plant supply contracts)

- Programme for the construction / completion of the works.

- The conditions of contract

- Site regulations.

- The Form of tender: the offer.

- Unconditional acceptance of the tender.

- Guarantees or bonds.

- A formal Agreement.

- Additions or variations of the above made during negotiations or subsequently by

agreement between the parties.

A normal contract document comprises but not restricted to the following:

a) Form of agreement

Although under English law, a valid contract may be formed purely by documents

constituting an offer and an unconditional acceptance, it is sometimes necessary or

advantageous to embody or confirm the contract by drawing up a formal agreement.

The standing orders of many public bodies, (for example local and country councils) require

that all contracts over a certain sum are so embodied in a formal agreement which has to be

signed and sealed as a corporate document on their behalf by certain officials they have

empowered to do so.

48

Confirmation of a contract in a formal agreement can be of value:

- To emphasize the formality and importance of the contract.

- To summarize the highlights of a complex contract.

- To stress that the contract is with the employer in cases in which the enquiry, tenders,

negotiation, and correspondence have all been handled by the engineer (in his role

as agent for the employer).

- To schedule the items forming the contract documentation.

- To tidy-up a contract situation when there have been extensive negotiations following

the tender and the contract documentation and details have suffered involved

modification.

b) Conditions of contract

The conditions of contract are the ‘Rules’ by which the contract is run. They set out

the rights and obligations of the parties and agree the action that will be taken by the

parties if various eventualities arise during the course of the contract. The range of

eventualities they cover varies from case to case depending on the nature of the contracts

the conditions of contract may run to several pages of print. For really large contracts,

they may extend to several volumes.

Contract conditions form much of the legal basis of the contract on which any ruling

by the courts would be made. Consequently they need to be written with care and

precision so as to be clear and unambiguous. Luckily many of the points to be covered are

common to a large number of types of contract and, in addition, experience has led to a

form of words which is generally acceptable to both parties. As a

consequence there exists a number of standard forms of conditions of contract which have

fairly wide recognition in the U.K and some which are recognized internationally. The

49

use of these can remove a lot of the need for composing new conditions for each and

every contract.

c) The Technical Specification

The technical specification describes in details the information provide by the contract

drawings and the BOQ. It describes in detail the work to be executed under the contract

and the nature and quality of the materials, components and workmanship. It may also

contain clauses specifying the order in which the various stages of the works are to be

carried out, the methods to be adopted in the execution of the work and details of any

special facilities that are to be provided by contractors or sub-contractors.

d) Bill of Quantities

The BOQ contains the schedule of items of work to be carried out under the contract

with quantities inserted against each item. These quantities are prepared in accordance

with CESmm3 – Civil Engineering standard methods of measurement 3. Due to the small

side of many of the drawings composed to the large extent of work involved in a contract

and the uncertainties about certain site conditions, the quantities inserted in a bill are

often approximate. Nonetheless, the quantities should be as accurate as the information

available permits and the descriptions against each item must conform to the actual work

involved.

In most cases, the unit rates inserted by the contractor against each item in the BOQ

normally includes the overhead charges and profit, but subject to the approach adopted in

pricing method-related charges and the adjustment item in the grand summary.

One of the main functions of civil engineering, BOQ is to provide a basis on which

tenders can be obtained, priced and compared. After the contract has been signed, the

rates in the priced BOQs can be used to assess the value of the work executed on

continuous basis, from the commencement to the completion of the project.

50

e) Contract Drawings

The contract drawings shows in details the nature and scope of work to be carried out

under the contract. The drawings should be thoroughly, comprehensively and clearly

detailed to enable the contractor to satisfactorily price the BOQ. The drawings should

include the site plan depicting the existing features at the site and the proposed work

including full descriptions and explanatory notes where such emphasis is desirable. The

more explicit arise bothering on the scope and character of the works. More so, ample

figured dimension should be inserted sufficiently to facilitate effective and accurate taking-

off of quantities and in setting constructional work on site. Drawings may incorporate or be

accompanied by schedules such as bar bending schedule for steel reinforcement,

manhole/sewer schedules etc.

f) Arbitrator

An Arbitrator is a person appointed by mutual consent of the parties to a project

dispute, to adjudicate on the dispute via an award which normally binds on the parties

concerned with the dispute. He (arbitrator) is in most cases a private person acting in a

judicial manner. An arbitrator must be a specialist or an expert in the project area where the

parties are in dispute.

If the parties to a dispute fails to appoint an arbitrator within one calendar month, of

either party serving on the other party a written notice to concur in the appointment of an

arbitrator, then they may have to resort to a natural body e.g. a professional body

recognized by the two parties to appoint an arbitrator for them.

An arbitrator must be neutral and unbiased against or in favor of any of the parties for his

award or decision to be final and binding on the parties or he runs the risk of

disqualification or have his award rejected.

g) Site meetings / Progress reports

51

Site meetings may be conducted on weekly fortnightly or monthly basis depending on the

nature, size and complexity of the project. The parties to a project site meeting often include

the consultants (employer’s representative) and the contractor or his representative, the

representative of the beneficiary of the project ( if different from the client) etc. It is the

satisfactory duty of the engineer or the consult to ensure that the contractor together with

nominated sub-contractors and suppliers comply with the specifications and standard of

workmanship in accordance with the conditions of contract and articles of agreement. The

minutes of the meetings are always complied and collated to form the basis for the monthly

or weekly PROGRESS REPORTS. This often includes valuation and financial statements

forwarded to the client or employer on regular bases while the execution of the project lasts.

a. Circumstances that couldn’t nave been reasonably foreseen before the signing of the

contract.

b. Additional requirements of the employer.

c. Compliance with new government orders and legislation.

d. Correction of errors or omissions in the contract drawings and contract bills.

e. Non-availability of materials. Goods or services specified in the contract.

f. Substations of materials, goods and workmanship specified in the contract.

h) Fluctuation

Fluctuation arises from charges in wages and other incidental expenses for labour as well as

prices of materials quoted in the contract bills at the date of tender. The employer is

compelled to entertain fluctuations only in terms of approved basic wages and emoluments

and certain materials and sections of the works as listed in the appendix to the contract. In

Nigeria, the prices contained in the contract bills are based on the rates o0f wages and

emoluments and other expenses payable by the contractor for labour costs in accordance with

52

the rates of wages fixed by FOBACEC, current at the date of tender and applicable to the area

concerned.

In a situation where the wages and emoluments are increased or decreased due to government

policy after the official date of tender, then the additional costs thereupon, shall be made

payable to the contractor accordingly. Similarly, the prices contained in the contract bills are

based on the prevailing market prices of materials in a given location at the date of tender.

This includes purchase tax (such as VAT) and import duty (if any). Here again the contractor

is entitled to additional claims if it is confirmed that the prices went up after the date of

tender.

5.20 Statement of the Scope of the Contract

The statement of the scope of the contract is made by the Employer in inviting tenders. It

introduces the subject of the contract and explains in broad terms what the employer will

require by way of work or plant from the successful Tenderer, and by when he will want to

be complete or in operation.

5.30 Data affecting the execution of the works.

Data affecting the execution of the works is issued by the employer with the invitation to

tender and includes such things as Site geological data, access, limitations on working hours,

local conditions, other work being carried out on the site, machinery, services and supplies

which the employer will provide for the contractor’s use, and so on. All such points may

affect the Tenderer’s costs and hence his offer.

Works and the more obvious the point at which the contract requirements have been

adequately fulfilled: in the absence of a precise specification the employer always tends to

expert more and the contractor to give less.

53

WEEK SIX 6.0 TYPES AND SCOPE OF CIVIL ENGINEERING CONTRACTS

Like any legal contract, a valid civil engineering contract posses three distinct traits

of offer, acceptance and consideration. A promoter (or client) propose

s for a civil engineering project and makes offer, with a clear consideration, to a contractor

formerly conveys his acceptance of the offer; a binding contract is automatically

established between the two parties. The types of contracts encountered in civil engineering

can be classified into fixed-price contracts such as (i) Bill of Quantities Contract, (ii)

Schedule Of Rates Contract, (iii) Lump-sum Contract; and non-fixed-price contracts such

as cost fee reimbursement contracts like (i) Cost-plus percentage contract, (iii) Cost-plus

fluctuating fee contract, (iv) Target Cost Contract, (v) Package-deal or Turnkey contract.

The types of contracts enumerated above are now discussed in details as follows:

6.10 Bills of Quantities Contract

In this type of contract, an un-priced Bill of Quantities, prepared in accordance with

Civil Engineering Standard Method of Measurement (CESMM), is inserted in the tender

document for every prospective contractor to price. This contract, also known as measure

and value contract, is the commonest and most widely used form of contract for works of

civil engineering construction of medium and large scale extent, where the quantities of the

bulk of the works can be ascertained from the contract drawings with reasonable accuracy

before the commencement of the work. The total sum tendered under this contract is the

sum of the individual items as priced in the bill, including any prime costs, lump sums, and

provisional sums The quantity of all items of work to be done as contained in the bill are

not approximate, they are exact, being measured as accurately as possible from the

drawings. When the work is constructed, the quantities are replaced by the measurement of

the actual quantity of work the contractor carries out under each item.

54

The advantages or superiorities of this type of contract over any other are that:

i) The contractor is paid for the actual amount of work carried out, thus limiting

the risk element borne by him.

ii) The method gives freedom to alter the work of construction and yet remains the

basis of fair payment between the client and the contractor.

iii) Adjudication of tenders is relatively straight forward as all tenderers price on a

comparable basis.

iv) The bill itself gives every tenderer a very clear conception of the type, scope,

extent and the details of the work to be carried out.

From the following, if this type of contract is properly handled, it promises to be the

most equitable type of agreement between the client and the contractor as it invites the most

competitive prices from the contractors and it leaves the way open to the engineer to

exercise his responsibilities properly by allowing him to alter the amount of work

undertaken so that it best suits all the revealed conditions at the site. This type of contract

also comes under the class of fixed-price contracts because the unit rates tendered by the

contractor for individual items in the bill are fixed. However, it does not give a fixed total

sum because the actual quantity of work measured in the field may be different from the

quantities of work measured from the design drawings; but if the construction follows the

design closely, the total price paid by the employer may not be far different from the total

sum tendered.

6.20 Schedule-of-Rates Contracts

This type of contract is used for execution of civil engineering operations where it is

not possible to put into bill of quantities, measurement of quantities based on the contract

drawings. A typical example of this is a contract for the sinking of a borehole for a water

supply scheme. It is frequently not possible to state well in advance to what depth a

55

contractor should go to sink the borehole to strike water of the required quantity. There are

occasions where it may be imperative to commence a construction work before design and

preparation of contract drawings; i.e before measurement of quantities can be made such

drawings. In this case a schedule of rates contract suffices. The contractor should be informed

that all the items in the schedule of rates are to be considered as provisional items.

This type of contract may take one or two forums. The client may supply a schedule

of unit rates covering each item of work and ask the contractors, when tendering, to state a

percentage above or below the given rates for which they would be prepared to execute the

work. Alternatively, and as is more usual, the contractors may be requested to insert prices

entered will enable the most favorable offer to be ascertained. This type of contract is suitable

for maintenance and similar contracts, where it is not possible to give a realistic quantity of

work to be undertaken. Another merit of this type of contract is that it can be used for

projects of long duration because the schedules can be prepared fairly quickly.

Also, during the execution of early stage of a project by a contractor selected from a

schedule of adequately detailed rates, a BOQ can be prepared for the remainder of the work.

This bill can be priced using the rates inserted in the original schedule by the contractor

already engaged on the site, or alternatively, competitive tenders can be obtained, and if

appropriate, another contractor can be engaged for subsequent phases. For instance, the

substructure of a power station can be measured and valued in accordance with schedule of

rates, while the substructure can be handled based on BOQ contract.

In as much as this type of contract is in a way similar to BOQ contract, contrasting

features between them should be appreciated. The differences are:

i) Quantities against the individual items are either not inserted or they are entered in

estimated amounts or in round-figure provisional quantities.

56

ii) There is no implied guarantee that all or any given proportion of the items will be

carried out; therefore, each item must carry its own overheads, and bring the

contractor adequate reward if undertaken in large or small quantity, irrespective of

the amount of work executed under other items. In a BOQ contract, the setting up

and overhead costs to the contractor will be spread over the bill items (except the

provisional items), in the knowledge that the great majority of theses items will be

carried out.

iii) More items are schedule for temporary work than usually appear in a BOQ (e.g.

items such as for setting up plant,etc) because the amount of temporary work that

a contractor may have to carry out is uncertain.

iv) The remainder of the scheduled items tends to describe operations by the

contractor rather than outputs, and the number of items is less than a BOQ.

This type of contract also enables the contractor and the engineer to cooperate at the

design stage in the in the development of new techniques in an effective and economical way.

The schedule of rates should ideally be an opportunity to discuss the relationship of plant

usage and site organization to the design of scheme.

6.30 Lump-sum Contracts

In this type of contract, the contractor undertakes to carry out certain specified works for a

fixed sum of money. Naturally, the nature, scope and extent of work to be carried out should

be clearly and unambiguously delineated in a well dimensioned and detailed drawing and the

specification for materials and workmanship should be well thought out to the understanding

of the contractor or his agents. BOQ is not required. This form of contract is suitable for

small scale projects that’s are carried out above the ground level and clearly visible, such as a

road resurfacing contract.

Lump-sum contracts can be used advantageously provided:

57

i) the job is not very large;

ii) the work required is precisely described in adequate details;

iii) there is no great risk attached to its construction;

iv) no large or numerous alterations are called for during construction.

Small projects like low cost houses, garages, depots, factory sheds or other buildings of

modest size and traditional design can be built under this type of contract; or the contract may

be used for the supply and building-in of equipment of different kinds. Quit often a large

BOQ contract may contain within it single items which are in effect lump-sum contracts for

portions of the work within the overall contract.

Advantages

ii) it eliminates rigorous accounting and measurement of works;

iii) it gives the client an assurance of a fixed total price;

iv) It gives the contractor a clear straight forward job to job to do.

Disadvantages

i) There is always a contractual dispute immediately the client or the engineer wants

an alternation of design leading to additional works during construction, or if the

job itself runs into unforeseen troubles;

ii) It is not an equitable system because one party to the contract may be unjustifiably

favoured to the detriment of the other.

6.40 Cost-plus percentage Contract

In this type of contract, the client agrees to pay the contractor a specified percentage

of the total cost of a project as management fee to reimburse him for profits and overheads,

over the above the actual costs of expenditure for procurement of materials, employment of

labour and hiring or acquisition of plant. The contract is relatively simple to operate and was

used extensively during the Second World War for defense installations. This type of contract

58

is vulnerable to abuse because there is no incentive for efficiency, economy and optimal

utilization of resources. For example, an unscrupulous contractor may want to take undue

advantage of apparent loopholes in the system to exploit the client because the less efficient

the contractor, the more the cost of the work and the more his profit.

The engineer in charge of the project will also not fare better because of efficiency

problem which might turn him into a sort of dictator as he has the authority to sanction the

contractor as he deems fit, thereby making him to work at cross purposes with matters are so

sanctioned, every invoice, pay sheet, plant record, materials sheet, etc, will probably have to

go before the client’s auditors before it can be finally authorized for payment.

This type of contract is only used in an emergency, for a limited period, before there

has been time to draw up some other form of contract. Otherwise, it is not a worthy form of

arrangement; it does not give enough freedom, it sows seed of mistrust from the beginning, it

saddles all parties with a great deal of paper work, and it is seldom efficient.

6.50 Cost-plus Fixed-fee Contract

This type of contract requires that the contractor be paid the actual costs he incurred in the

execution of the work plus a fixed lump sum to cater for is profits and overheads, which has

previously been agreed upon and does not fluctuate with the final cost of the project. The

fixed fee may be tendered in competition with other contractors, or it may be negotiated

between the client and the contractor. Although, no real incentive exists for the contractor to

secure efficient working arrangement on the site, he has the advantage of earning the fixed

fee as quickly as possible to release his resources for other jobs. This form of contract is also

beneficial to the client.

This type of contract may be highly acceptable and useful depending on the efficiency

of the contractor. With the ever growing global competition, there is no doubt that this type of

contract would be the right way to tackle difficult civil engineering projects. It puts the

59

engineer and the contractor in harmonious working relationship, so that they can act jointly to

produce the highest quality of workmanship possible at the most economical cost. It also

gives great freedom to adopt different methods of construction or to tackle

Unusual problems or wriggle out of unforeseen troubles. However, going by the

unpredictability of human perfection, the client and the engineer must be doubly sure that the

contractor is competent, reputable and can undertake the work with the highest degree of

accuracy.

6.60 Package-deal (All-in) Contract

Under the package-deal contract, the client frequently using the services of an engineer,

normally gives his requirements in concise, detailed outlines to contractors who are asked to

submit full details of design, construction and cost, and probably including maintenance of

the work for a limited period. A situation whereby the individual contractors are required to

prepare a design that will favour him in the long run and the overall cost of the project may

not be within the client’s budget.

Furthermore, the evaluation and comparison of the contractors’ tenders may be complicated

as each contractor is likely to interpret the client’s brief in a different way, necessitating

adjustment that may be needed to reduce the tenders to a common basis for the purposes of

comparison. This type of contract has been used extensively in chemical and oil industries

and for the design and construction of nuclear power stations. It is a type of contract that

sometimes finds favor with overseas clients or contractors. This type of contract may sound

attractive, but it may be subject to operational difficulties especially in times of inflation and

when the basic technology is changing rapidly.

60

WEEK SEVEN 7.0 STUDENT EXCURSION

� 7.1 Student shall visit a construction site within Kaduna Metropolis.

� 7.2 The Lecturer/Instructor is required to make all necessary arrangement with a construction site.

� 7.3 It is expected that the site will be an active one; where students will also be expected to appreciate what the have learnt to date and use their mind to follow what they are to be subsequently taught.

61

WEEK EIGHT 8.0 PROJECT PLANNING AND COST CONTROL

Planning can be applied in varying degrees of detail. Depending on the stage at

which it is being carried out. As an example, for construction work, project planning is

usually divided into pre-tender planning, pre-contract planning and short term planning on

site.

1) Pre-tender project planning is done to allow the estimator to arrive at an estimate of cost

based on the proposed methods of working and an estimate of the time required

carrying out the work. Programming at the pre-tender stage is usually in an outline form

to consider only the phasing of the main operations, since much information is not at

the time available.

2) Pre-contract project planning is carried out when the contract has been won and the

project is considered more fully. Project planning at this stage includes the overall

programme, labour schedules, plant schedule, and material schedules e.t.c. The overall

programme should not break the operations does exxeccives or it will become

unrealistic.

3) Short term project planning on site is done in greater detail and the programmes at this

stage are broken much further. The cost control must be carried out to make project

planning effective, as without cost control project planning loses much of its value. It

must be applied continuosly to update the plans and to enable reconsideration of list of

the work ahead in the light of what has already taken place.

The braking down of task is greater detail for short term project planning on site

could be acheaved using a programmed network techniques.

This is where our discussion shall be focused. However, the resulting overall programme

could be converted to bar chart. The bar chart method presentation also shows enough

information, e.g. float times on all activities could be shown is often argued by some

project consultants or managements that for small projects, planning by bar charts may be

drawn direct and are quite satisfactory. Also, many contractors use bar charts as they are

thought to be less involved.

The use of network techniques requires producing programme showing movement of

resources starting with drawing a network, analyzing it and the scheduling which also

62

involves resource allocation. These techniques are particularly applicable to “one off”

projects and hence are of considerable use for many construction projects.

8.1 PROJECT PLANNING-NTWORK TECHNIQUES

The planning and control of a large-scale project may be accomplished by utilizing an

activity network as the modeling technique. One example being the critical path method.

The CPM is classified under the deterministic procedures. Another example is the

Programme Evaluation and Review Technique. The PERT is classified under the

probalistic procedure. Acceptance of these procedures has been widespread by project

consultants/management for the following reasons:-

1) The concepts are easy to understand and apply.

2) They introduce objectivity in project planning and control.

3) They reduce the complexity of the project planning and control process by breaking

the project down into its individual components.

8.2 DETERMINISTIC P ROJECT PLANNING (CPM) PREPARATI ON

The first stage in the preparation of CPM diagrams is to make a list of the activities to

be used. The amount of detail required in the breakdown depends on many factors, such as

the size of the project or the stage of planning i.e. pre-tender, pre-contract, or short term. One

activity in a CPM network drawn at the pre-tender stage may be broken down into a number

of activities at a later stage. To avoid misunderstanding, diagrams are arranged so that time

flows from left to right. When drawing network diagrams it is important to remember that

“off site” activities such as delivery of plaster board can be critical and must therefore be

included on the diagram.

8.21 METHODS OF PREPARING A (CPM) NETWORK

There are three (3) basic methods of preparing a diagram.

i) the activity-on-the-arrow system-AOA

ii) the activity-on-the-node system-AON

iii) Event or mile stone system- which largely represented by the PERT method.

We shall endeavor to concentrate on AOA system.

8.30 THE ELEMENTS OF AN ACTIVITY ON- AN -ARROW NETW ORK

1) The principal component of an AOA is an . An arrow is used to

represent an activity which in itself is a “time”-consuming element of the programme and

also represent the consumption of certain resources such as labour, money or the use of plants

or materials or energy.

63

The length and shape of the arrow presented in a diagram is significant. The direction of

arrow as earlier mentioned indicates direction of workflow, usually left-to-right. The part of

an arrow usually represents the starting point of a particular activity. A brief description, of

what the activity represents as part of the task and the expection time (duration time) usually

written against the arrow. As each activity is considered the following questions should be

asked.

1) Which activity must be completed before this activity can start?

2) Which other activities cannot start until this activity is completed?

3) Event- These are represented by numbers. That is at either end of the arrow there must

appear an event. This event is mile stone or point, node, connector, at which an

operation, the activity is completed or another can start.

“Tail” “Head” or or preceding succeeding event event Fig1: Showing events 1&2

The cycle at the head of the arrow represents the event, or the mile stone, or the point in

time when one can say that the activity ( ) is completed. The cycle at the tail of the

activity arrow is the time one can say activity can commence.

However, an event may be represented by

, , , , or any geometric plan shape. In brief, one can say that an event is the start and/or finish of an activity or group of

activities.

8.40 PRINCIPLE OF DEPENDENCY

All networks are constructed logically on the principle of dependency. Dependency principle

states that:-

i) No event can be reached in a project before the activity which immediately

precedes it is completed.

1 2

64

ii) No activity can be started until the event which immediately precedes it has been

reached.

This principle is one of the basic logic of a network diagram. The two exceptions to these

basic rules are the starting event and final event of the network diagram.

Events

Activities

Activity 9-10 cannot start until activities 7-9& 8-9 are completed. An event will not be said to

be reached until a number of activities preceding it have been completed. This event 9 cannot

be said to have been reached until activities 7-9 & 8-9 preceding it have been completed.

8.41 MERGE EVENT & BURST EVENT

Merge Event: - An event into which a number activity enter and one (or several) leave

is known as “merge” node. An event such as D in fig.3 below can be described as a merge

event because a number of arrows merge into it.

Burst Event: - Event that have one (or several) entering activities, but generating a number of

emerging activities is known as “burst” node. An event such as F in Fig 4a and 4b can be

described as a burst event.

Fig: 3: showing “merge” event- D

7

8

9

10

6

A

C

B D

Merge event

E F

65

One activity entering

Several activities entering

Fig 4b: showing “burst” event-F

8.42 Common Errors in Logicality of Network Diagrams

Two errors in logic may come about when drawing a network, particularly if it is a

complicated one. These are known as looping and dangling errors.

Looping error- Consider the diagram in fig 5 below.

P

R Q

8.43 Dummy Activity

‘Dummy’ activities are sometimes necessary in an arrow diagram. These do not take

time to perform nor consume resources. They are used either to make the sequence clear (See

fig7.0 below) or to give a unique numbering system (see fig 7.1, 7.2, 7.3). If a ‘dummy’ is not

used here, two activities would have the same reference .e.g. joinery 1st fix and elect work 1st

fix (see fig 7.1) would have the same preceding and succeeding event. This is not acceptable

when using a computer for planning and analysis. It is therefore essential that a unique

numbering system be used.

(See Fig 7.2&7.3)

Burst event

F

Burst event

8 9

10

19

21

23

18

20

22

Fig5: Showing error due to looping.

66

Fig.7.0 Activity 21-23 cannot start until activities 19-21 and 18-20 are completed, but activity

20-22 can start when activity 18-20 is completed and is not dependent on activity 19- 21.

Joinery Joinery

1st fix 1st fix

Elect-work 1st fix

Elect-work

1st fix

Joinery

1st Fix

Fig 7.1, 7.2, 7.3 represent the same

Situation Elect-work 1st fix Fig: 7.3

We can see that activity R depends on activity Q which inturn depends on activity R and R

on Q.

If looping like this appears to arise, the logic underlying the diagram must be fault, and the

construction of the diagram must be re-examined.

Dangling error- Similarly, the situation represented, below is equally at fault.

Fig6: Showing error due to dangling

This is because activity represented by the dangling arrow (activity 9-11) is under

taken with no result.

Note:

i) All nodes, except the first and he last must have at least one activity entering and

one activity leaving them. This we have earlier pointed out.

9

10

9 10

10

9 11

10

8 9 10

11

67

ii) All activities must start and finish with a node, except the first set of starting

activity/activities and the last set of finishing activity/activities.

iii) It is extremely important at the project planning network design stages that as

much of the work as possible are arranged to be carried out concurrently, if the

shortest possible programme period is required. This is possible for all mutually

exclusives activities.

There are two occasions when dummies are used:

1) Identify dummies

2) Logic dummies

Dummies can be represented thus:

(as in fig 2)

D

O

8.44 Identify Dummies

When two or more parallel independent activities have the same head and tail events, the

identify of the activities could not be lost (computer/analysis) as in fig 7.1. It is thus useful to

insert “identify dummy” to avoid this situation thus fig 7.2 & 7.3.

Note: It is useful to insert the dummy at the tail rather than at the head of the activities. Thus

fig 7.3 is preferable to fig 7.2

8.45 Logic Dummies

When two chains have a common event ye they are in them selves wholly or partly

independent of each other, then an error in logic could unwittingly arise.

A K A K L B B L Fig: 8 Logical dumming presentation use to separate activities A&K and B&L 8.50 NETWORK CONSTRUCTION

The first thing to be done is to identify the programme’s objective. The objective will be

represented by the last event in the network to which all various branches of the network

must eventually coverage.

15

15

15

68

It is sometimes inevitable in the majority of network that the logic will demand that, in

number of instance, one activity arrow crosses another. By arranging or re-arranging the

diagram carefully, it is possible to avoid too many such situations.

When the diagram has been drawn on a piece of paper, it must be very critically examined

to ensure that it represents the required and desirable method of carrying out the work. Also

examine carefully that the logic is correctly endured and that the p4rinciple of dependency

applies logically throughout the diagram.

Having considered and reconsidered the network to ensure that the planning logic is

sound, the necessity arises to estimate the duration (time) which will be involved in carrying

out each of the activity, in order that the scheduling process may be commenced.

8.60 ACTIVITY DURATION

Activity duration (shown on the arrows) can be in days, weeks or months, depending on

how detailed the diagram is to be. The duration for a contractor activities would be arrived at

by using past records of outputs, synthetic times based on work study, e.t.c. The gang sizes

and plant type to be used would be the ones which give optimum performance at this stage

irrespective of the requirements of other activities. Sub-contractors and suppliers should be

approached in order to obtain realistic duration for their activities. Adequate time period shall

also be allowed for studying of project working drawings before starting the programme. One

basic difference in CPM and PERT occurs from the different method of arriving at the time

estimate. In CPM only one time estimate is made, and this value Yik is treated as a known

value

(deterministic approach).

Similarly, there are two chronological times TEi and TLi associated with each event or

node of the graph.

TEi= Earliest possible time of occurance of event, i, which would not be incompatible with a

given project and TLs.

From the network relationships between events and activities, it is possible to develop the

following recursive relationships for computing TEi and Tli:

TEi= TE

69

Max (TEh+Yhi) for all (h, i) E P- - - - - - - (i)

And

Tli= Tls

Min (Tlk-Yik) for all (I, k) EP- - - - - - - -- (ii)

Epselon E= included in project p.

From these equations, it is possible to compute the following information about each activity

included in the project p.

1) Earliest starting time, TEi

2) Latest starting time, TLj-Yij

3) Earliest completion time, TEi+ Yij

4) Latest completion time, Tlj-Yij

5) Maximum available time, TLj-TEi

6) Slack time, TLj-TEi-Yij

The information above becomes the basic foundation on which management decisions

about a particular activity are based. Slack represents the amount of latitude available to the

decision maker in the scheduling of that activity. If the slack=O, the activity is critical

because the sequencing decision is no longer controlled by the decision maker. In CPM it can

be shown that there is always a connected chain of critical activities from project start to

project end.

8.61 PROJECT DURATION

The project duration is the minimum time in which it can be completed with the activity

times assigned to it.

The duration of the project will be determined by the longest path through the diagram.

This is known as the critical path.

If the time required for any activity is affected, this will automatically effect the project

duration.

8.62 APPLICATION OF NWT 1) Construction of projects

2) Overhauling and maintenance programmes

3) Setting up of new organization

70

4) Organizing very big functions like national or international games, big exhibitions,

e.t.c.

5) Defence establishments.

8.63 LIMITATIONS

1) Network technique is simply a tool to help the management; hence its effectiveness

depends on how well it is used by the management.

2) Its accuracy depends on the estimation of the data used in the network.

3) It is useful only, if it is updated regularly and decisions for corrective actions are

taken timely.

ADVANTAGES

1) Detailed and thoughtful planning provides better analysis and logical thinking.

2) Identifies the critical activities and focus them to provide greater managerial attention.

3) Network technique enables management to forecast project duration more accurately.

4) If is a powerful tool for optimization of resources by using the concept of slack.

5) It provides a scientific basis for monitoring, review and control, to evaluate effect of

slippages.

6) It helps in taking decision (i) to overcome delays, (ii) on crashing programme (iii)

optimizing resources, and (iv) on other concrete actions.

7) It helps in getting better co-ordination amongst related fields.

8) It is an effective management tool through a common and simple language, providing

common understanding.

8.70 TECHNIQUE OF ESTIMATION: What techniques of estimation are available to

improve the job planning process. Well, there are time (PERT), human and material, and

value costs. In many cases these methods are used in combination and they can contribute to

better result, if used wisely. It is always assumed, that planning and estimation are identical

twins. They go hand-in-hand when it comes to management of resources.

Time resources is best handled with PERT methods. Progress Evaluation Review

Technique (PERT), its basic concept is that the program is divided into discrete detailed

scheduled tasks which are drawn up into an integrated network.

All the significant variables of time, resources, and technical performance are allocated to

each task or activity. This system creates a systematic reporting technique which enables

71

management to compare actual performance with the original program plan, thereby

permitting a continuous check on the program status.

The operation of PERT can be divided into the following five broad categories:

1) Establishment of objectives

2) Creation of plans

3) Establishment of schedules

4) Evaluation of performance

5) Arrival at decision and action.

Drwg

The corrective feedback permits the project supervisor to implement changes in the program

or plans of action or schedules if the program objective of schedule or cost is in danger or

not.

The PERT system uses a unique language. The following are the most fundamental

terms which are used:

1) Activity: An element of work effort in a program.

2) Event: A specific point in the program usually representing the start or completion of

an activity. An event does not have any dimension in time or effort.

3) Network: A graphic representation of a program consisting of activities and events

which is known as inter-connected paths.

4) Most likely time, m: The most realistic estimate of time that it would take to

complete an activity.

72

5) Optimistic Time, a: The shortest period of time that the completion of an activity

would consume.

6) Pessimistic Time, b: The longest period of time that the completion of an activity

would consume.

7) Expected Time, Te: The period of time that is predicted for completing an activity.

The expected time is statistically derived from the most likely, optimistic, and

pessimistic times as expressed by the formula:

6

4 bmaTe

++=

8) Cumulative Expected Time, TE: The earliest date that can be anticipated for the

completion of a specified work efforts. TE is the summation of all the expected time

Te along a particular path.

9) Latest Allowable Date, TL: The latest date on which an event can occur without

delaying the completion of the program. The latest allowable time is calculated by

subtraction the expected elapsed periods or expected times (Te) of activities from the

date of the last event. If the end date coincides with the date represented by TE, then

TL = TE.

10) Positive Slack Time: The amount of excess time predicted for the achievement of a

particular event. Negative slack indicates the amount of slippage that exist prior to

reaching a particular event. Slack time is the difference between the latest allowable

date and the expected date (TL-TE).

11) Critical Path: The path of a network that requires the longest period of time to

complete. It is the path that possesses the smallest positive slack or the greatest

negative slack.

73

Drwg

The above diagram shows a network using the PERT technique. The arrows represent tasks

to be done, while the cycle, show what are known as events. Events, in PERT language, are

simply stages in the progress of the project. The tasks, or activities, require manpower,

material, facilities and other resources, while events represent specific accomplishments that

are the result of work.

If you were building a house, for example, the first activity might be digging the

foundation. This would be an activity or task that would required the use of resources and

would be indicated on the diagram by an arrow.

The completion of this task, which would mean you were ready to go on to the next step,

would be an event and would be indicated by a circle. The longest path in terms of time

through the network is the critical path of the project. It indicates a series of jobs which must

be done in sequence and which will take longer than the other sequence of jobs that can be

going along simultaneously. It is critical because the time spent on this path determines the

total time to be spent on the entire project. There is always a need to shorten the time spent on

critical path, so that the time in total, spent on the project would be shortened.

Material Estimation: The estimates of material cost are fairly straight forward, normally

based on the current level of market prices. For short term projects (1 year or less) the current

market prices are used. However, for project spanning a long period, the material cost may be

modified to anticipate the price the company expects to pay at some future date. The

modification factor is usually based on price indices and trends.

74

WEEK NINE 9.0 MATERIAL QUALITY CONTROL MEASURES

Details of the quality of materials of materials to be used in the works will be contained in the

material and workmanship specifications and these should be read carefully and mastered.

All materials to be used must be certified by the supervising engineer and samples must be

kept permanently in the engineer’s site office. If the contractor cannot find the material

specified and alternative but approved equal may be certified for use by the engineer. Testing

to ensure quality may have to be done and a sample of material and record of test results kept.

Quality control procedures for common engineering materials are as follows:

9.01 Concrete

To ensure the required characteristics of concrete, concrete must be properly constituted with

good quality materials, properly mixed, properly transported, properly placed, properly

worked and properly cured. Any laxity in any of the processes described may result in poor

finished concrete. Therefore all processes must be monitored by the supervising engineer.

Quality of Constituent Materials a) Coarse and Fine Aggregates

i) Both Coarse and fine aggregate must be sharp, clean, free from silt, clay,

metallic, plastic, organic materials or other constituents which may ne

injurious to the finished concrete.

ii) Coarse aggregate should be angular or rounded but not flaky.

iii) Depending on the type of concrete, grading must be specified, where not

specified, a well graded aggregate is preferred to a gap graded or single size

aggregate.

iv) The maximum size of the aggregate must be as specified; a rule of thumb is

that it should be about 5mm less than the minimum cover to reinforcement.

v) Aggregate should be inert, if the chemical nature of an aggregate is not known

it should not be employed for concrete.

vi) Sieve fine aggregate if necessary.

vii) Coarse aggregate may be washed but only dry aggregate can be in the

concrete; washed aggregates contain unquantifiable amount of water which

has not been taken into consideration in design.

9.02 Cement

75

Depending on the project, various types of cement of cement may be specified other than

the popular Ordinary Portland Cement. However, if a contractor wishes to use one other

than specified, the properties must be investigated to ensure that it will not have adverse

effect on the short and long term properties of the concrete.

(i) Check each batch of cement by random sampling.

(ii) Where cement replacement materials are to be used, check that proportion used is as

specified.

(iii) Cement must be powdery , lumps are sign of hydration, reject lumpy cement, no

sieving of cement must be allowed.

9.03 Water

This is sometimes taken for granted but this should be monitored properly. Water for

concreting should be:

i) Clean and clear.

ii) Potable or fit for drinking.

iii) Not containing chemicals which may be harmful to the concrete in the short or long

term. High level of chloride or sulphate should be avoided.

9.04 Admixtures

Admixtures are chemicals that are used to modify the wet properties of concrete to either

delay solidification or assist workability. Whatever may be reason for usage or specification,

ensure that:-

i) The admixture to be used has proper specifications and documentation from the

manufacturers, keep information in your record.

ii) It does not contain injurious material to the concrete and workers.

iii) It will not affect the strength properties of the concrete adversely , if it will ensure

provision is made to cover this. Some workability agents delay strength gain,

therefore prop removal should be delayed accordingly.

iv) If mixing is done on site, ensure that the right dosage isused.

9.1 Mixing

i) Mixing should be done according to mix design. The engineer should ensure

proper specification of mix. Specifying a mix as 1:2:4 is not complete until the

water/cement (w/c) is added. If a mix is been prescribed, it should be specified

whether it is by weight or by volume. Nigerians generally work to volume but this

must be specified. NB:

76

Avoid specifying mix except you are dead sure of the quality of all materials to be

used.

ii) Where only grade has been specified, the contractor must submit results of trial

mixes which he aims to use to Satisfy the specification before the commencement

of work or any casting is done. If no such results are available, trial mixes must be

made on site and tested at the appropriate age before any casting is allowed.

iii) Mixing must be thorough and until a uniform consistency is obtained. This is best

achieved mechanically but it is possible with proper hand mixing (no rush job

should be allowed)

iv) Mixing water should be controlled by volume or weight and not visually.

9.2 Transportation

Where the concrete is to be transported over a long distance or it has to wait for a long time

before placement, mechanical agitation should be ensured. Transportation should not result in

segregation.

9.3 Placement

i) Test workability at the beginning of each casting and do so at regular interval, eye

test of flow can be misleading (for slump test, aim for 50-75mm slump). Test must

be carried out by you and according to the relevant code.

ii) Concrete should not be poured from a great height to avoid segregation and it

should not be moved over a great distance from the point of placement by the use

f vibrator.

iii) Concrete should be placed in small layers, each layer being worked properly

before the next layer. Interlayer working should be discouraged.

iv) Concrete is best worked with a mechanical vibrator and this should be

encouraged. If hand vibration is to be employed, it should be done thoroughly and

through the depth of each placement, tapping at the top to produce a smooth finish

is not adequate.

v) Form work of large depth placement should be provided with inspection windows

to ensure that the full depth is filled with compacted concrete and that there are no

large air pockets.

vi) Joints in casting must be at specified locations.

vii) Joints in continuous pours should be at non-critical locations (at middle third of

span for slabs or beams). Casting joints should be well cleaned and prepared

before continuation of casting.

77

9.4 Curing

A good concrete mix, properly placed and worked will still produce less than desirable

strength, if it is not properly cured. Therefore the curing regime must be properly monitored

and ideally, the curing regime of the structure must be the same as that of the test samples.

The idea of curing test specimens under water for 28 days but wetting structure for only 2

days should be discouraged totally. The engineer must approve the curing method of the

contractor and therefore he must ensure that it will produce the desirable strength of concrete.

9.5 Property Monitoring

On most concrete works, the property of concrete which is used to monitor its various

characteristics and strength is the compressive crushing strength. This is measured either on a

cube or cylinder specimen of appropriate size. The engineer must ensure that:

i) At least, three (3) specimens are taken for each casting and for each time the test

is to be carried out. Therefore if one is interested in the 7 days, 14 days and 28

days strength of the concrete, nine (9) specimens must be taken randomly during

the casting.

ii) He takes the specimen himself and not delegates others or ask the contractor to do

it.

iii) The specimen is taken according to the relevant code of practice. For example the

specimen must not be compacted with a vibrator but a tamping rod as specified by

the British code.

iv) The specimen is marked as soon as possible to identify it and the location of pour.

v) The specimen is removed from the mould in his presence and put under the

appropriate curing regime.

vi) The specimen are taken out from the curing place on the day of the test and taken

out for testing under his supervision.

vii) Whenever possible, witness the testing and the recording of results.

viii) He compares the strength obtained to the specified strength making allowance for

normal engineering tolerance and normal statistical distribution of data. Plot or

tabulate result and use any of the assessment methods for analysis.

9.6 REINFORCING BARS

The engineer should ensure that reinforcements are:

i) Are of the types (plain or deformed) and size specified.

ii) Are free from rust or pitting.

78

iii) Are of the specified yield strength. Tensile strength test must be carried out on

each tone of reinforcement, on samples taken randomly from each size and type of

bars.

iv) Are not brittle and can be bent to the required shape. Bending test on each size

and type of bar must be carried out on each batch.

v) Free from grease or oil, this is very important for plain bars which derive their

bond strength solely from adhesion.

vi) In rehabilitation works, existing reinforcement that has rusted if still going to be

used must be wire brushed and may be coated for protection (depending on the

reason for rusting).

9.7 STRUCTURAL STEEL

The engineer should ensure that:

i) The dimensions and weights of sections are as specified.

ii) The specified grade of steel is used.

iii) The steel is weld-able.

iv) Bolts and nuts are of the right type, size and number.

v) Welds are of the right type, thickness and length.

vi) Bolt holes are well formed and are at least the minimum distance form free edges.

vii) Appropriate anti-rust and fire retardant treatment are applied.

viii) Bracings are not omitted.

ix) Joint constructions are as designed.

9.8 Timber

The Engineer should ensure that:

i) The right type of timber with appropriate structural strength is used. If possible

approve ONLY timber from known and certified company.

ii) Timbers are straight and have uniform dimension through out their length.

iii) Timber is well seasoned.

iv) Members do not have knots or holes in areas which may adversely affect their

strength or which may attract cracks or splitting.

v) Jointing is by the appropriate type of joints.

vi) Nails used are of the right size which will keep the members together and pass the

maximum force that the member will be subjected to.

vii) Appropriate anti-termite/wood pest treatment is applied. Check the depth of

penetration of treatment by cutting through full depth of timber pieces.

79

viii) Timbers with holes indicate pest infestation, reject immediately.

ix) Timber is appropriately stored on site (under a roof and stacked with separators

for further seasoning).

80

WEEK TEN 10.0 CONCRETE MIX DESIGN

10.1 Definition Cement concrete is a very useful constructional material whose properties can be

modified readily at will. The desired properties of concrete can be obtained by using

ingredients in a certain proportion. Thus, determining the relative amount of materials is

known as mix design. Hence, mix design can be defined as the process of selecting suitable

ingredients of concrete and determining their relative quantities for producing concrete of

certain (specified) minimum properties as strength, durability and consistency etc, as

economically as possible.

10.11 Purpose of Mix design

From the definition of mix design, it can be seen that the purpose of mix design is two

fold as follows:

2. To achieve the stipulated minimum strength and durability.

2. To make the concrete in the most economical way.

Cost wise all concretes depend mainly on two factors

(a) Cost of materials and

(b) Cost of labour.

The cost of form work, batching, mixing, transporting, and curing e.t.c. is nearly the same for

good as well as bad concrete work.

Thus, to achieve economy, the main attention should be directed to the cost of materials. As

the cost of cement is many times more than other ingredients, thus the attention mainly

should be directed to the use of little amount of cement as possible consistent with the

strength and durability. Mix proportions provided by the designs are called as prescribed

mix.

10.12 Objects of Mix design

The objects of mix design are:

i To decide the proportions of materials this will produce concrete of required properties.

ii. The mix proportions should be selected in such a way that the resulting concrete is of

desired workability while fresh and it could be placed and compacted easily for the

intended purpose.

81

iii. The fresh concrete should be fluid enough to fill the form work and surround the

reinforcement fully and

iv the hardened concrete should develop required strength and durability.

10.13 Factors affecting the choice of mix proportion

According to IS - 456-1978 and IS-1345-1980.The design of concrete should be based

on the following factors:

1. Grade designation 2. Type of cement

3 Max.nominal size of aggregate 4. Grading of combined aggregate

5. Water – cement ratio 6. Workability

7. Durability.

� Grade designation

Grade designation specifies the characteristics compressive strength of concrete.

� The characteristics compressive strength is that value of concrete strength

below which not more than 5% of test results are expected to fall.

� It is the major factor which influences the mix design.

� Depending upon the degree of control on site, the concrete mix should be

designed for the mean compressive strength (which is a little higher than

the characteristics strength).

10.2 Types of cement

The type of cement is important as the rate of strength development depends mainly on

the cement. The choice of the type of cement depends upon the requirements of its

performance.

i. When very high compressive strength is required, Portland cement conforming to IS -

8041-1978 and

ii. for mass concrete work, low heat Portland cement conforming to IS- 269-1979 can

be used.

10.21 Maximum nominal size of coarse aggregate.

The maximum nominal size of coarse aggregate is determined by sieve analysis and is

designated by the sieve size higher than the size on which 15% or more of the aggregate is

retained. It is governed by

i. the size of the section and

ii. The spacing of the reinforcement. According to IS-456-1978 and IS-1345-1980, the

max.size of the aggregate should be as follows:

82

It should not be more than 1/4th of the minimum thickness of the member

It should be less by 5 mm than the minimum clear distance between the reinforcement.

It should be less by 5 mm than the minimum cover to the reinforcement

It should be less by 5 mm than the spacing between the prestressing cables.

for normal structural concrete work, the maximum size of aggregate may be

used as 38 mm

for high strength concrete it may be 10mm to 20 mm.

10.22 Grading of combined aggregate

In a concrete mix, the relative proportions of the fine and coarse aggregate is one of the

important factors which affect the strength of the concrete.

� For dense concrete, it is essential that the fine and coarse aggregates be well

graded.

� The locally available aggregate generally do not conform to the standard grading.

In such situations the aggregate should be combined in suitable proportions, so

that the resulting grading is close to the desired grading. The aim of combining the

aggregate is to:

o obtain a grading close to the coarse grading of standard grading curves,

o obtain the most economical mix having the highest permissible

aggregate cement ratio.

The aggregates can be combined either by analytical calculations or graphical, using the

method of Road Note 4.

10.23 Water / Cement ratio

The compressive strength of concrete at a given age under normal conditions of curing

mainly depends upon water/ cement ratio.

Lower the water – cement ratio within limits, grater the compressive strength and vice –

versa.

A number of relationships between compressive strengths and water – cement ratio are

available, which are valid for a wide range of conditions. The generalized relationship

between water – cement ratio and compressive strength of concrete is shown on Figure 1.1.

10.24 Workability

For satisfactory placing and compacting of concrete the workability is controlled by many

factors as:

shape and size of the section to be concreting

83

quantity and spacing of reinforcement

method of transportation

placing and compaction of concrete

The insufficient workability will result in :

i. incomplete compaction,

ii. less strength and durability.

There are various methods of determining the workability of concrete, measure by different

methods. Hence, it is desirable to decide the test method before starting the concrete work.

For comparable concretes workability measured by different, methods is shown in Table 1.1.

10.25 Durability

It can be defined as the resistance to internal and external deteriorating influences. The

requirements of durability may be achieved by restricting:

the minimum cement content and

minimum water-cement ratio as given in Table 1.2.

10.26 Quality Control

The strength of concrete is never constant. It varies from batch to batch. This variation

may be due to:

i. the variation in the quality of constituent materials,

ii. variation in mix proportions,

iii. variation in the quality of batching and mixing equipments available,

iv. Quality of workmanship and supervision. e.t.c

Controlling these factors is important to minimize the difference between the minimum

strength and characteristic main strength of the mix, thus reducing the cement content. The

method of controlling these differences is called quality control.

10.30 Grades of concrete and requirements for structures and general construction

Now let us look at the grades of concrete and their requirements for structures and

general construction. This is important since a mix should be designed to produce a specific

grade of concrete for a specific use, having the required workability and characteristics

strength not less than as given in Table 1.3.

Terminologies in mix design

i. Preliminary test:

Is defined as the test conducted in a laboratory in the trial mix concrete produced in the

laboratory for designing a concrete mix before actual concreting at site, to verify:

� the strength of concrete

84

� determine the adjustments required in the mix (if needed ).

ii Controlled concrete

The concrete for which mix is designed after carrying out preliminary test is called

controlled concrete.

iii Ordinary concrete

The concrete mixing adopted without carrying out preliminary test is called ordinary

concrete.

Note: Student should know that for all important civil engineering works controlled

concrete should be used.

iv Work test

A test conducted either in the field or in a laboratory, usually on the specimen made

on actual site of works, out of concrete being used in the works is called works test.

v Nominal mix concrete.

Where it is not practical to use controlled concrete, ordinary concrete of nominal mix is used.

Nominal mix grade for this type of concrete vary from M5, M7.5, M10, M15 and M20 as

per I.S 456 – 1978.The proportion these mixes are given in Table 1.4.

10.40 Methods of concrete mix design

There are various methods of mix design concrete. Some of these methods are

enumerated below:

(i) Arbitrary method

(ii) Minimum void method

(iii) Maximum density method

(iv) Water- cement ratio method

(v) Fineness modulus method

(vi) Standard deviation method

(vii) American method of mix design

(viii) Graphic or Road Note method.

(ix) Indian Road Congress IRC-44 method

(x) High strength concrete mix design

(xi) Mix. design base on flexural strength

(xii) ACI committee 211-1 method

(xiii) Rapid method of mix design

(xiv) Department of Environment (DOE) mix design method

(xv) Mix design for pumpable concrete

85

(xvi) Indian standard recommended (IS 10262-1982) method

Now a day out of the above methods, the following are commonly used:

1. ACI committee 211 method

2. DOE method

3. Indian standard method

4. Rapid method of mix design

Our lecture will now examine the DOE design method in detail (step 9).

10.50 THE DEPARTMENT OF ENVIRONMENTS DESIGN METHOD

(DOE METHOD)

The DOE method of mix design is an improvement over Road Note No.4.This (Road

Note 4) method of concrete mix design or proportioning mainly is based on the extensive

field and laboratory experiments carried out by Road Research laboratory in U.K .The Road

Note No.4 method was published for the first time in 1950.This method of mix design was

most popular and widely used up to 1970 all world.

The DOE method was first published in 1975 and revised in 1988.The DOE method

of mix design is applicable to all types of concrete mixes including roads, while Roads Note

No.4 was applicable to roads and air fields only. This method can also be used for concrete

containing fly ash. DOE method is a standard method of mix design in NIGERIA now. This

method used the relationship between water/cement ratio and compressive strength

depending on the type of cement and aggregate used. The water contents required to give

various levels of workability, as very low, low, medium and high expressed in term of slumps

or Vee Bee time or compacting factor, are determined for the two types of aggregate as

crushed aggregate and gravel. This method is suitable for mix design of normal concrete

mixes having 28 days cube compressive strength up to 75 MPa for non air entrained concrete

.The step by step procedure of mix design is given below

10.51 Step – by – Step Procedure to DOE mix design

Determine the target mean strength from the specified characteristics strength.

Target mean strength = specified characteristics strength + standard deviation × Risk

factor.

(Risk factor is taken on the assumption that 5% of result are allowed to fall below the

specified characteristics strength).That is, the target mean compressive strength ft at 28 days

is given by ft = fc + KS.

Where:

86

ft = the target mean strength at 28 days

fc = the characteristic strength at 28 days.

S = standard deviation. For the initial value of mix design the value of standard deviation

may be adopted from Table 1.5.

K = a statistical coefficient known as tolerance factor or risk factor. The value of K may be

adopted from Table 1.6.

Selection (fix) water/cement ratio from Fig.1.2 and Table 1.7

From Table 1.7 the approximate compressive strength of concrete made with free

water/cement ratio 0.5 is obtained,

From the same Table 1.7, find out the 28 days strength for a given type of cement

and type of coarse aggregate (C.A),

Now mark a point on the y – axis of the Fig. 1.2 equal to the compressive strength,

read from Table 1.7, which is at w/c ratio is 0.5,

From this point draw a parallel dotted curve nearest to the point of intersection,

using this curve, read off the w/c ratio as against target mean strength.

The method will be clearer from the work example later presented.

Student should note that:

even when the water-cement ratio is fixed, the compressive strength of concrete is

influenced by various factors such as

� type of cement

� type of aggregate

� maximum size of aggregate

� surface texture of aggregate

Thus it is desirable to establish relation between the strength of concrete and free

water/cement ratio for the materials to be used and site conditions

Determine water content for the required workability

Water content for the required workability is next determine, taking into account the size of

aggregate and its type from Table 1.8 and 1.9.

10.6 Determination of cement content

The amount of cement can be determined from the total water content and w/c ratio.

i.e. Cement content = weight of water

w/c ratio

87

The quantity of cement obtained by the above relation should be compared with

the minimum cement content specified from durability considerations as given in

Table 1.10 and 1.11.

The higher of the two quantities should be adopted.

o If maximum cement content is specified, then the calculated cement content

should be less than the specified maximum cement content.

10.61 Determination of total aggregate content

Note 01: For determining the total aggregate content, the estimation of wet density of fully

compacted concrete is required. This can be obtained from Fig.1.3 (for approximate water

content and known specific gravity of aggregate)

Note 02: If the specific gravity of aggregate is not known its value for uncrushed aggregate

may be taken as 2.6 and 2.7

Note 03: For crushed aggregate specific gravity may be assumed as shown on curves A and

B of the Fig.1.3.The aggregate content is determined by subtracting the weights of cement

and water cement from the Fig.1.3.

10.62 Determination of fine aggregate

The proportion of fine aggregate in total aggregate is determined from Fig 1.4

Fig 1.4 (a) is for 10 mm size,

Fig 1.4 (b) is for 20 mm size, and

Fig 1.4 (c) is for 40 mm size coarse aggregate.

The parameters involved in Fig 1.4 are

i. max.size of aggregates,

ii. The water content,

iii. Degree of workability and

iv. The percentage of fine aggregate passing through 600 micron sieve.

Knowing the proportion of fine aggregate from Fig 1.4 the weight of fine aggregate may be

obtained by multiplying the total weight of aggregate by this proportion.

Knowing the fine aggregate the weight of coarse aggregate can be found.

The coarse aggregate can further be divided into different fractions depending upon the shape

of aggregate. Generally figures given in Table 1.12 may be adopted.

10.7 Worked example as class-room demonstration

QUESTION:

88

A civil engineering work requires target concrete cube strength of 45 MPa at 28 days. Design

the concrete mix for the desired work given the following information.

(1) Type of cement = Ordinary Portland cement

(2) Max.size of uncrushed aggregate to be used = 20 mm

(2) Low workability, slump = 10.30 mm

(3) Specific gravity of aggregate = 2.65

(4) The aggregate percentage passing 600 micron = 50%

(5) Exposure to concrete is moderate

(6) The cover to the reinforcement to be provided is 25 mm.

Determine the target strength from the relation

Target strength = specified characteristics strength + standard deviation × Risk factor

In this case the target strength is directly given as 45 Mpa at 28 days.

Find out the water/cement ratio for targeted strength 45 MPa

For finding out the w/c ratio, refer to Table 1.7.From this table for ordinary Portland

cement and uncrushed 20 mm aggregate the 28 days strength is 42 Mpa.

From Fig.1.2 find the point of inter section of 42 MPa at 0.5 water/cement ratio. Through

this point draw a doted line curve parallel to the neighboring curve. Now draw a

strength line from the desired strength on y-axis, where this line cuts the curve, draw

a perpendicular on x-axis which will give w/c ratio for the targeted strength i.e. 45

Mpa.

From this curve for 45 Mpa strength, the water / cement ratio comes out 0.54.

For uncrushed aggregate of 20 mm max.size aggregate approximate water content from Table

1.8. is 160 kg/m3.

For moderate exposure and 25 mm cover maximum w/c ratio from durability consideration is

permitted as 0.5.

Actually the lower value of the two should be adopted. Hence, adopt w/c ratio 0.5 water

content for 10 to 30 mm slump from Table 1.8 is 160kg/m3.

Cement content

From w/c ratio 0.5 and water content 160 kg.

Cement content = 160 = 320.4 kg

0.5

Note: From durability consideration, the quantity of cement should be used as 350 kg/m3

.Thus adopt greater cement content as 350 kg/m3

89

Determination of density of fresh concrete

From Fig.1.3, for water content of 160kg/m3 , 20 mm uncrushed , the wet density of

concrete = 2490kg/m3

Determination of total weight of aggregate

Total weight of aggregate=Total weight of concrete-Weight of water-Weight of cement

= 2490 – 160 - 350

= 2490- 510 = 2180kg/m3

Fine aggregate (F.A) from Fig.1.4 (b) for slump 10 -30 and aggregate passing through

600 micron as 50% for w/c ratio 0.5

F.A = 27%

. 2180 × 27

. . Weight of fine aggregate = 100 = 588.6 = 589 kg/ m3

Weight of coarse aggregate = 2180 – 588.6 = 1591.4 kg/m3

� Estimated quantities in kg/m3 are:

(a) Cement = 350kg/m3

(b) F.A = 588.6kg/m3

(c) C.A = 1591.4kg/m3

(d) Water density = 160kg/m3

(e) Wet density = 2490kg/m3

Note: From these quantities

i. the trial mix is prepared,

ii. samples cast and

iii. tested at 28 days to judge the suitability of concrete for the desired work.

iv. if need arises, adjustment in quantities be made.

90

WEEK ELEVEN 11.0 Construction Machine, Plants and Labour

11.01 INTRODUCTION

Civil engineering construction (practice) requires the extensive use of construction machinery

(plant) and equipment for proper execution. Plant and equipment frequently encountered in

Civil Engineering jobs include:

� Bulldozers

� Scrapers

� Graders

� Cranes

� Loaders

� Hoists

� Logging Arches

� Trenchers

� Tractors

� Pipe Laying Equipment

� Winches

� Compactors

� Trucks

� Air Compressors

� Poker Vibrators

� Concrete Mixers etc.

With the ever increasing cost of labour and rapid growth in construction technology, it

becomes imperative to use more and more mechanical equipment in association with the

available manpower for construction works. Largely because of the temporary nature of

construction organization on site, when compared with that of a factory based production

unit, the mechanization of the industry has been a slow and indifferent process. Only with

very careful consideration, investigation and planning can be the most suitable equipment for

any particular project can be chosen.

Such planning must be backed up by a thorough experience of the use of all types of plants,

together with an understanding of the engineering fundamentals involved. Correctly chosen

91

and well operated plant will enable a construction project to be completed on time and on

budget (cost).

No contractor can possibly own outright every single item of mechanical equipments that he

will be called upon to use over a period of years. There are many (items of ) specialist

equipments that he may require frequently, thus, he cannot afford , however, in an already

short of capital situation to have it tied up in idle machinery that is seldom taken out of the

plant-yard (for use on site). On the other hand, there is no item of plant that can be said to be

universally standard, although much of the equipment currently in use falls into broad

standard classes. A contractor must buy equipments on which he estimates that he can make a

profit. His assessment whether to buy the plant outright or to hire it as required must be

premised on a very sound economic investigation.

There are some obvious circumstances in which he will have little difficulty in making up his

mind. Such situation might well be one in which a single project is large enough to bear the

cost of a specific item of plant, irrespective of its ultimate salvage value or whether its

subsequent employment is likely. (e.g. crane).

Many large, long term earthmoving contracts may well support the purchase of earthmoving

equipment for their exclusive use. Many other short term types of contracts will bear the cost

of a concrete-batching or mixing plant if concrete is to be mixed in large quantities.

11.1 CLASSES OF MECHANICAL EQUIPMENT

There are numerous ways of classifying mechanical equipment according to its:

� Function

� Mobility

� Mode of Operation

� Motivation

It is convenient in the first instance, to classify all mechanical equipment into three broad

classes in accordance with its mode of operation and production since the calculation of

output is of prime consideration when making rational (productive) selection. The

classification is:

a) That where the machines have an intermittent cycle of work; - such a machine operates a

series of work cycles, each of which is a complete operation on itself. The rate at which

work cycles are carried out determines the production or output of the machine. Most

earthmoving equipment falls into this category. Mechanical Shovels are typical examples.

Concrete mixers of the batch type and Pile-Drivers are examples which are not

earthmovers.

92

b) That where the machines have a continuous flow type of production; - In this category

comes most of the equipment using pipe and/or conveyor belts for distribution purposes.

This class includes pumps of all types (including those for pumping), conveyors for

distributing concrete, concrete aggregates and execrated materials, and air compressors.

c) That where the machines have intermittent production flow consequently falls between

classes (a and (b above. The class of the equipment is of the type that often operates

continuously over a defined surface area but, on completion of its particular sweep,

ceases operation and has its position adjusted so as to resume production in another area.

An example of such an operation is the use of Grader in working on a road formation. It

grades through the length currently under construction and at the end of its sweep run, it

turned, repositions, and commence grading another sweep run. This cycle of operation is

continued until the whole area to be graded is covered.

11.2 General Factors in the Selection of Construction Equipment

Three of the most important points to be considered in selecting mechanical equipment for a

given construction project are:

a) Physical dimensions and nature of the work involved.

b) The duration of the project and

c) The specification for the work (cost).

Having arrived at what is necessarily an appropriate answer to these three points, the question

of the combination of manpower and machines, which is estimated will enable the work to be

carried out in the best possible time combined with the lowest possible cost, must be

considered. Much discussion will take place at the pre-tender planning stage, and during the

cost estimating process, about the general construction methods which will be used for a

particular contract, and particularly so for all the major operations which make up the

contract.

Having decided the method of construction, it then becomes necessary to translate this into

terms of mechanical equipment which is either available or can be made available for the

contract, and which can be obtained for a minimum cost.

11.3 Selection Process

Equipment is productivity and utilization must be given adequate consideration in the

selection process. High productivity and utilization of equipment will bring about a reduction

in cost and an increase in profit made. The most effective way of judging the degree of

utilization often (item of mechanical) equipment is to spread the direct charges, which

become payable over the output of the machine in such a way that unit costs are obtained. For

93

instance, In the use of excavation machine if the hire charges are related to each cubic meter

of material which is excavated, and the figure so obtained is then compared with that allowed

at the tender stage, some measure of the Actual Efficiency against Expected will be obtained.

It has been stated earlier “no contractor may own all the plant that he may need over a period

of years”. Hiring of equipment is usually adopted to balance up the contractor’s mechanical

equipment fleet. The overall profitability of the contracts being carried out by the contractor

is of prime importance and plant must be bought and hived with a view of maximizing this

profitability. The selection of the equipment to be bought and those to be hired should be

informed by a sound economic analysis of the project(s) involved.

Sound and thorough planning is the only basis on which plant selection can be nationally

made. Many of the construction processes which take place on a site requires for the

successful completion, the combination of a number of mechanical equipment.

94

WEEK TWELVE 12.0 EARTH MOVING EQUIPMENT

12.10The Utilization of Earth-Moving Equipment

The selection of equipment for carrying out the earth-moving process is one of the most

critical of all in the field of mechanical equipment utilization. The principles which govern

the proper selection of such equipment can also be appli9ed in modified form to most other

types of plant.

It is not possible to lay down very rigid rules concerning the selection of plant to carry out a

specific earth-moving operation. Almost all operations of this type ca be carried out by a

variety of different types and sizes of machines. Many combinations give comparable results.

There are , however, a number of fundamental principles, some or all of which must be taken

into a/c for the proper careful consideration of every operation. An understanding of the

principles which are involved will lead to a sounder and more rational choice of machine

with the likelihood of a higher rate of production at a lowest cost.

The factors to be considered are as follows:

a) The physical properties of the materials to be moved.

b) The rolling resistance of the ground to be covered.

c) The gradient of haul-roads and working surfaces.

d) The capability of the machine to accelerate under given conditions.

e) The coefficient of the running surface.

f) The altitude and ambient temperature of the working site.

g) The capacity efficiency of the soil container.

h) The working efficiency of the machine.

i) The efficiency of the machine operator (human).

j) The weather conditions at the time of operation.

k) The condition and length of the haul-roads.

l) The service and downtime of the machine.

Some of these factors concern materials to be moved and some of the external conditions

which prevail at the time of the movement. Some are concerned with the characteristics of

the machines chosen to do the moving and one, at least, concerns the individual who operates

the machine.

95

Each factor must be considered on its own merits and the total effect of all the relevant

conditions must be assessed for a given situation.

12.2 FUNDAMENTALS OF EARTH-MOVING

Most Civil Engineering works/constructions involve a great deal of earth-moving operations.

That is the movement of earth materials from where it is not needed to where it is needed.

The success of individual civil engineering contractors can be tried to the degree to which the

fundamental principles of earth moving are understood and applied to equipment on any

given job.

12.3 Materials

Earth-Moving is a sequence of changing the layer or strata of the land OR the transportation

of the earth’s surface according to the desires and designs of men.

Earth resists being moved (generally), materials that make up the earth undergo a process of

geological changes as they are being moved from their respective geological deposit. The

changes are the results of the properties of the materials.

However, the nature of the material is less important. What is of most important is the

physical properties of the material which in effect influences its loadability by the earth-

moving equipment.

Loadability is the degree of ease with which earth material can be dug and loaded from their

natural state. This is a function of the loading characteristics of the material which in turn is a

function of its physical geological properties. Earth’s surface is made of sizable number of

elements, compounds and mixtures.

For the purpose of earth-moving, materials are classified into 3:

1) Rock Materials: - This includes rocks formation and hardpan or boulders. Usually

their loading process involves blasting or ripping into boulder or large stone sizes

before loading. The choice of equipment for loading depends on the loading (and

unloading) characteristics of the material. Other materials are masonry and concrete

structures and pre-cast concrete, large boulders etc.

2) Soil Material: - This includes geological deposits ranging from coarse to fine grains.

It also includes quarry dust and other river weathering material subjected to

denudation. They include- gravel, sand, silt and clay.

3) Rock-Soil mixture: - These are earth materials made of combination of rock and soil

particles of different gradation.

96

Earth materials may have moisture depending on weather conditions, drainage, and retention

quality of the material. Materials being moved have three properties that are of vital concern

to the earth-mover/equipment used. These are:

i. Weight of Material

ii. Swell and Load Factor

iii. Compatibility

One should note that moisture content of an earth material seriously affects its loadability.

The factors influences moisture content of an earth material varies. Some of which are

beyond human control e.g. Rain, weather condition. The moisture retention property of earth

material e.g. humidity, sun heat etc. can be controlled to some extent, but is also difficult and

very expensive. The technique of control to be adopted is a function of quantity of soil.

Weight: Weight is a measure of mass of an object as it is attracted by force of gravity. The

greater the weight of soil, the greater the effort/force required to move the earth. Thus the

weight of material is a pointer of how heavy is the material?

The power carrying capacity and the volume capacity of an equipment needs to be balanced

for a better decision on choice of equipment. This is because the volume of a material has

direct relation to its weight (Vol vs Wt). any additional volume beyond the volume carrying

capacity could decrease the efficiency of the equipment (i.e. every system has its load limit).

In addition to the problem of load limit, the weight of earth materials also:

Affects the way a scraper will load, a bulldozer will push, or a motor grader

will cast material.

Weight also affects the turning, maneuvering and hauling in high speed

ranges is directly influenced.

More effort is required to move heavier materials (measure of weight).

Weight also affects performance of the equipment

Satisfactory performance will be achieved for an equipment (load limits) if volume and

weight capacities are nor exceeded.

Swell:

This is the ability of earth material to increase in volume when it is removed from its natural

state (bank) to a loose state. It is usually expressed as a percentage of the increase in volume

when compared with the original.

i.e. Swell 100 volOriginal

in vol Change ×=

97

100 volOriginal

in vol Increase ×=

Note: if the swell of a dry clay = 30%. This statement means that a 1.0m3 of clay in the bank

(i.e natural state) will fill a space of 1.3m3 in loosened state.

Load Factor:

This is the percentage decrease in density (kg/m3) of a material from its natural state is its

loosened state. The concept of swelling and load factor is important in earth moving. This is

because generally earth materials are measured in bank metres.

3/ mkgVolume

MassDensity == …………………….. (a)

Load Factor yBankDensit

LooseDensity = ……………………. (b)

Percentage Swell = 100 1Factor

1 ×

−Load

……. (c)

100%

Bank State

Vb

l b

Mb

b

bb V

M=l ………………………. (1)

b

bb

MV

l= ………………………. (2)

But LV bV>

bM = LM …………… Constant

L.F =B

L

l

l

L

b

l

l⇒

Also percentage swell = 10011000

×

−=−=×

∆∆

b

L

b

bL

V

V

V

VVV…………Constant

………………………………………………………………….

(100+x)% Loose VL l L ML

L

LL V

M=l ………………………. (3)

L

LL

MV

l= ………………………. (4)

………………………………………………………………………………………………………………………………

98

But from equ (2)× (4)

Percentage swell = 10011001 ×

−⇒×

−L

b

b

b

L

L

M

M

l

l

l

l

Percentage Swell = 1001L.F

1 ×

−

Percentage Swell =( ) 1001.L 1 ×−−F

Illustration

18 cubic metre (heaped) scraper.

Material is dry clay.

Density of 2945kg/cubic metre (bank),

Swell is 40%

Load Factor = 0.72

Solution

18m3 loose clay = (bank) 72.018 3m×

= 386.12 m

If 12.96 3m was known

Swell = ( ) 3184.596.124.0 m=+

Check

Then loose volume to be moved = 184.596.12 +

= 3144.18 m loose

= 318m given

Compatibility

Compaction; Compaction of earth material is necessary so as to prevent:

− Sinking and

− Distortion

……….………………………………

…………..

…………..

………….. ……

……..

Loose Compacted

Void Reduction

Denser

Moisture Reducer

99

It is also necessary for a better finishing. There are various methods in the construction

industry of achieving adequate degree of compaction. Some of these methods are:

i. Rolling (rollers)

ii. Tampering (use of tamping rods)

iii. Pulverizing

iv. Vibrating

v. Addition of water

Usually for a given volume of earth material, the compacted state is such that material

particles come closer together (grain-to-grain contact) than the state of bank enhances

(usually due to overburden and addition of water) when in the bank.

Illustration

Bank volume Loose Volume Compacted Volume

31m 33.1 m 375.0 m

100% by volume 130% by volume(30% swell) 75% by volume (25% shrinkage)

200kg (Normal) 200kg (Swell) 200kg (Shrink)

− We can see that when a given volume of earth is well compacted, it is expected that

its compacted volume will be lesser than the bank volume. (i.e. Shrinkage).

− Compacting effort is greater than overburden pressure.

Pay Volume:

The pay volume is the basis for payment of earthmoving work. This depends on the

specification of choice adopted by the engineer preparing the tender-document. Pay volume

could be either (on the basis of):

i. Bank Volume

ii. Loose Volume or

iii. Compacted Volume.

However, for most Civil Engineering work the bank volume is adopted as the basis for

payment of earth-moving works.

……….………………………………

…………..

…………..

………….. ……

……..

Bank State Save volume heaped and compacted

(i) Density Increase (ii) Volume Reduce (iii) No change in

Mass

100

WEEK THIRTEEN 13.0 MAINTENANCE

13.1 Introduction

Every machine is thoroughly tested and inspected by the manufacturers before selling it

and by the purchaser before it is put to use. When it is used, it will be subjected to wear and

tear hence proper attention should be given to protect the machine and its components from

undue wear and thus protect them from failures. A proper attention means lubrication,

cleaning, timely inspection and systematic maintenance. Maintenance of a machine means

efforts directed towards the up-keep and the repair of that machine.

A major part of the expenditure is generally on the men, material and maintenance in an

industry. Every machine will require repairs even if it is best designed, hence the repair must

be done at such a time when it may have least disruptions, i.e. machine may be repaired when

it is not being used or its use may be postponed without affecting the production of the whole

concern. Therefore, checking of the machine is generally done when it is not in operation, so

that the defect, if any, can be immediately and easily rectified without causing extensive

damage to the plant.

In this way, we say that maintenance is responsible for the smooth and efficient working of

an industry and helps in improving the productivity. It also helps in keeping the machines in a

state of maximum efficiency with economy.

Realizing the high importance of maintenance of plants and equipments, National

Productive Council, undertook the survey of engineer industries, and found that due to failure

of the plants, equipment and machineries, non-availability is 28 percent. Looking to this high

percentage of failures, it is essential that the engineering units should improve their

maintenance system.

13.2 Maintenance Department

Success of manufacturing concern largely depends on its organization and the proper

selection of persons engaged for the design and operation work. Production in the concern

depends largely on the maintenance of plants. Hence, the organization of the maintenance

should be such that a proper maintenance and over hauls etc. , can be done economically and

effectively. Maintenance department is generally kept under the control of works manager,

who is responsible for the production. A sample organization of maintenance department in a

big concern is shown (indicating different functions) in the following line diagram:-

101

1. Maintenance of cranes, hoists, lifts etc.

2. Maintenance in the plant including repair checking, servicing, lubrication. Etc.

3. New installation. Each superintendent is responsible for the maintenance, overhauls, checking, repairs etc. He

should be an experienced person and should be able to decide the quantum and periodicities

for inspection and overhaul etc. Some changes in the organization may be done in the

factories depending upon the considerations.

Chief Maintenance Engineer

Works

Mechanical Maintenance Engineer Electrical Maintenance Engineer Civil Maintenance Engineer

Supdt. Plant Maintenance

Supdt. Repair shop

Supdt. Power house (Mech)

Phones supervisor

Supdt. Power house (Elec.)

Supdt. Power Maintenance

Supdt Building

Maintenance

Supdt. Road maintenance

Supdt. Sanitation and Water Supply Maintenance

n

1. Machine Maintenance, shop repair.

2. Fitting Checking etc. shop of maintenance.

3. Weldi

102

Types of Maintenance

Generally, maintenance can be done in the following two ways:

1. Breakdown maintenance.

2. Preventive maintenance.

In the first case of maintenance, repair can be done after the breakdown occurs while in the

second case maintenance is done on the basis of prediction or on the basis of periodical

checking.

13.3 BREAKDOWN MAINTENANCE

Breakdown of a machine can occur due to the following two reasons:

(i) due to unpredictable failure of components which cannot be prevented;

(ii) due to gradual wear and tear of the parts, which can be eliminated to a large

extent by regular inspections, known as preventive maintenance. From

experience it can be decided that, when a part should be replaced, so that

breakdown can be avoided.

In breakdown maintenance, defects are rectified only when the machine cannot perform its

function any longer, and the production department is compelled to call on the maintenance

engineer for the repairs. After repairing the defect, the maintenance engineers do not attend to

the machine again until another failure occurs.

In this type of maintenance, repair shall have to be done on failure, thus it may disrupt the

whole production. If it is performing an important work. This method is much expensive also

due to increase of depreciation cost, payment to idle operators, overtime to the maintenance

staff for doing the emergency repairs.

13.4 PREVENTIVE MAINTENANCE

Preventive maintenance is sometimes termed as “planned maintenance” or “scheduled

maintenance” or “systematic plant maintenance” etc. It is an extremely important function for

the reduction of maintenance cost and to keep the good operational condition of equipment

and hence increases the reliability. Preventive maintenance aims to locate the sources of

trouble and to remove them before breakdown occurs. Thus it is based on the idea

“prevention is better than cure”. Scheduled maintenance is always economical than

unscheduled maintenance, as we all know that “a stitch in time saves nine”.

Best safeguard against costly breakdowns is to inspect, lubricate and check up the

equipment as frequently as possible. To take full use of equipment and to maintain it reliable

condition, necessary measures should be taken to prevent overloading, dampness, negligence

and misuse of machines. Frequency of inspection should be decided on the basis of the

103

importance of the machine and its delicacy. This periodic inspection or checking helps to find

out the reasons leading to breakdown and to rectify them when they are in minor stages. Thus

the repair can be done when one wants to do it, i.e. when it has least effect on the production

schedule. Further this repair requires lesser time as compared to that of breakdown repair and

thus down time is reduced by doing preventive maintenance.

Objects

Preventive maintenance has following main objects:

1. To obtain maximum availability of the plant by avoiding breakdowns and by reducing

the shutdown periods to a minimum.

2. To keep the machine in proper condition so as to maintain the quality of the product.

3. By minimizing the wear and tear, preserve the value of the plant.

4. To ensure for the safety of the workers.

5. To keep the plant at the maximum production efficiency.

6. To achieve all the above objectives with most economical combination.

13.5 Functions or Element of Preventive Maintenance.

Following are some of the important functions of the preventive maintenance Programme:

1. Inspection or check ups.

2. Lubrication.

3. Planning and scheduling.

4. Records and analysis.

5. Training of maintenance staff.

6. Storage of spare parts.

1. Inspection or check ups. Inspection is an essential function of the preventive

maintenance Programme. Crews kept for this purpose should be well trained. These

crews carry out both the external and internal inspection. External inspection means to

watch for and detect defects from abnormal sound, vibration, heat, smoke etc, when

machine is in operation; while internal inspection means inspection of internal parts,

such as gears, bushes, bearings, tolerances in the parts etc., during the period when the

machine is under planned shutdowns.

Frequency of inspection should be decided very carefully, as too less inspection may

cause breakdown, as defects could not be traced out and rectified immediately; while

too much inspection means wastage of machine time and labour productivity. Hence,

frequency should be decided on the basis of past experiences and the scheduled

Programme for inspection is chalked out.

104

For the purpose of inspection machines can be categorized as:

(i) Important machines: These are those machines which can disrupt whole of

the production are delicate and require much time for the repair. More stress

should be given for the inspection of these machines and schedule for

inspection, cleaning, lubrication, should be adhered to rigidly.

(ii) Ordinary machines: Frequency of inspection can be kept as low as they do

not effect the production considerably.

2. Lubrication: Mechanical components like gears, bearings, brushes and other friction

surfaces etc., give good performance for long periods, when they are systematically

lubricated. Systematically lubricated, Systematic lubrication means the application of

right type of lubricant at the right time, at the right place and in right quantity. For

lubrication, a schedule should be prepared and should be followed strictly.

3. Planning and scheduling: Every preventive maintenance work should be pre-planned

in detail on the basis of the analysis done on the past records. A scheduled Programme

thus prepared should be followed strictly. Thus Programme should be in detail

specifying the points requiring daily, weekly, monthly, half yearly or yearly attention.

4. Training of Maintenance Personnel: For the success of preventive maintenance a

sound training is essential for the maintenance personnel. Hence, the technicians and

supervisors are trained to carry out maintenance, inspection and repairs in a systematic

way.

5. Storage of Spare Parts: Sometimes machine remains idle for want of spare parts for

considerable time and thus it affects considerably loss of production. But the judgment

and experience of high order is required for deciding the number of such parts, as

storage of a large number of parts must be determined by considering different factors

such as source of supply, delivery period and availability of that spare part in the market.

Standardization will help to reduce the spare parts inventory and will also help in

specialization of maintenance of particular type of machine.

13.6 Advantages of Preventive Maintenance

Following are some of the important advantages of efficiently planned and well

executed preventive maintenance Programme:

(i) Reduction in production downtime.

(ii) Lesser overtime pay for maintenance personnel.

(iii) Lesser number of standby equipments is needed.

(iv) Less expenditure on repairs.

105

(v) Due to planned spare parts replacement, lesser spare parts are needed to store at all

times.

(vi) Greater safety to employees because of reduced breakdowns.

13.7 Maintenance Procedure

Maintenance should be done considering all the above mentioned factors. Daily

maintenance is done by the operators themselves. Before starting the work of their shift,

cleaning, oiling and greasing should be done by the operators. For this purpose,

manufacturers used to issue maintenance instructions for their machines, which should

strictly be followed.

Preventive maintenance of the machine depends largely on the operators. Hence, as far as

possible, one operator for each machine be allotted; and when the same machine is used in

more than one shift one operator for each machine for each shift be allotted. This system has

following advantages:

(i) An operator gets used to the sound and working of his machine and notices any

change immediately, which helps in investigation and rectification of the defect

then and there. If operators are changed frequently, immediate check – up and

timely repair cannot be possible.

(ii) It is easy to pin-point operators with bad operating habits,. To remove these habits

training can be arranged or disciplinary actions can be taken as the case may be.

(iii) The machine will remain in good conditions.

Periodic maintenance is generally conducted by the maintenance crew, specially trained for

this purpose. The period should be decided on the basis of past experiences as explained

earlier. Apart from this, operating instructions should carefully be followed by the operators.

In case any abnormal sound or behaviour is noticed in the machine, he should immediately

bring this into the notice of maintenance crew, so that the defect can be rectified immediately.

Care must be taken that it may not be left for the later date.

Inspections and lubrication schedules should be strictly followed. Inspection schedule should

include the inspection of tools, accessories and other equipments.

13.8 Requirements for Good Preventive Maintenance

For achieving preventive maintenance of high order, following are some of the essential

requirements:

1) Good supervision and administration of maintenance department.

106

2) Proper control of work i.e. priority be fixed with care and after consultation with

production engineering department.

3) Correct, clear and detailed instructions be given to the maintenance crew and to

the operators.

4) Operators should be well trained.

5) A good lubrication Programme should be chalked out.

6) Proper maintenance record should be chalked out.

7) Adequate stock of spares should always be kept.

8) Surroundings should be dust free and clean with proper ventilation and

illumination.

9) Manufacturers of the machine should be consulted as and when required.

10) Maintenance department should remain in contact with planning and purchasing

department in deciding the type of machine tools to be purchased. A machine tool

to be purchased should be of best design, adequately safe, good lubrication

arrangements, minimum of moving parts, easy availability of spares etc.

107

WEEK FOURTEEN 14.0 EFFECTIVE METHODS OF TRANSFERRING KNOWLEDGE

AND SKILLS TO SUBORDINATES.

14.01 INTRODUCTION

a) Knowledge, as it relates to engineering practice, could be defined as, the information

obtained, by way of formal or informal education or training project. In other words,

knowledge is a power that motivates the principal actors of an engineering project in

carrying out their duties specifically and efficiently. Hence knowledge is acquired

through a training process.

b) Skill, on the other hand, could be defined, also as it relates to engineering practice, as

the ability to apply acquired knowledge in order to get desired results. Skill is the

technological know-how for certain engineering operations. Skill should improve with

experience gained on the job.

c) Knowledge and skill are, therefore, complimentary in the execution of engineering

projects as knowledge without skill could produce slow and uneconomical results,

while skill without knowledge of the fundamental could yield unsafe and uncertain

results. Knowledge and skill, hence, must be transferred from one part of the

engineering organizational structure into the other so as to be able to obtain reliable

results from the project execution. The process of transfer of knowledge and skill by a

superior to a subordinate is an art on its own, which when carefully studied and

understood by the superior becomes a skill.

14.02 PARTIES INVOLVED IN THE TRANSFER PROCESS

From the foregoing, it is evident that the transfer process of knowledge and skill is

from the superior to the subordinate.

A common distinction made in many organizations from superior to

subordinate can be seen in fig. 1.0.

Drwg

108

A supervisor is nay person who is in charge of and is responsible for the actions,

efforts and behavior of one or more other people. A supervisor exercises formal

authority as conferred by the organization and is therefore in a formal leadership role,

exercising authority and accepting responsibility for personnel in his group or

organizational unit.

By virtue of historical usage and custom,. There is a status connotation with

the terms ‘supervisor’ and ‘Manager’. In many organizations a supervisor refers to a

foreman, group leader, or some low-level manager who heads a group of workers,

usually at the bottom level of the organization.

In some other organizations, supervisors are the subordinates of the managers.

In such cases, Managers have greater authority and higher responsibilities.

The Operative Workers are those personnel involved in performing the

operative tasks such as, designing, creating, researching and developing, installing,

constructing, producing, manufacturing, operating and maintaining the product,

machine, system of service.

14.20 PRINCIPLES OF KNOWLEDGE AND SKILL

The principles to be considered for effective transfer of knowledge and skill to

subordinates shall be from two perspectives, which should both be satisfied. These

are:

d) Transfer by engaging the principles of effective supervision

e) Transfer by engaging the principles of effective scientific, technical and technological

teaching.

The first perspective outlines principles that tend to create the necessary socio-

psychological environment for the transfer process form the superior to the

subordinate while the second perspective outlines the principles that should be

adopted in technically actualizing the transfer process. As mentioned earlier, both

perspectives are complimentary in order to achieve maximum efficiency in the

knowledge and skill transfer process.

14.30 TRANSFER BY ENGAGING THE PRINCIPLES OF EFFECTIVE

SUPERVISON

1) Treat each of your subordinates as a distinct and valued individual. Show respect and

courtesy. Get to know and understand him – his personal interests, family background,

qualifications, experiences, education and training etc.

2) Give praise and credit when due. It is far better to:-

109

i. Praise

ii. Give due recognition and encouragement for work well done,

Than to

iii. Criticize

iv. Belittle and

v. Discourage subordinates.

Where possible, indicate what contribution that effort has made to the organization

and let other personnel ‘especially superiors’ know about the good work.

3) Continually stress and reiterate the organization’s objectives .point out to your

subordinates the target that your organizational unit is aiming for and when you expect

such to beaclieved .This would enable them develop interest in the relevant knowledge

and skill your want to impart on them.

4) Remember the importance of self interest to all individuals. Attempt to integrate

individual self interest and goals with the organization .

5) Try to aim for high ideals and standards of ethical conduct, in practical and realistic

terms .Remember that there is always the tendency for subordinates to follow your own

example.

6) Never reprimand any individual subordinates in front of others especially his peers or

subordinates. Reprimands privately, make sure of your facts and always listen to the

subordinates side of the story.

7) Always show confidence .Never show disappointments .Do not show that you are

worried even if you are. Do not have regrets, show hope, optimism and belief in the

cause .

8) Learn to delegate and train your subordinates accordingly, give clear, simple and direct

instructions and then trust your subordinates. Encourage people to accept greater

responsibilities and to undertake a variety of tasks.

9) Always listen and head the advice and suggestions made by your subordinates. They can

sometimes see things you have overlooked. Have a flexible mind and adapt your actions

to charged situations.

10) Be loyal to your subordinates and in turn you’ll find they will become loyal to you. If you

make a mistake, admit it.

11) Always try to simplify the problem. Sort out the wheat from the chaff. Do not become

immersed in details. Sometimes, certain details may be important sort out the essential

details and concern yourself with important issues.

110

12) Always retain a sense of humor, especially when things look bleak. It is better to belittle

one self rather than to belittle or mock others. Integrity and honesty are important to both

your superiors and subordinates.

14.40 TRANSFER BY ENGAGING THE PRINCIPLES OF EFFECTIVE

SCIENTIFIC, TECHNICAL AND TECHNOLOGICAL TEACHING

1) Give detailed explanations of the required procedure involved. Try to explain a

justification of these procedures from first principles.

2) List and discuss the various alternatives available for carrying out a specific construction

procedure e.g. concrete placing, formworks, reinforcement arrangements etc. for different

structural elements. Compare the pros and cons of each alternative and mention to your

subordinates their order of priority as regards to usage.

3) Give practical demonstrations in relevant cases e.g. as in the use of the rebound hammer,

use charts, tables and other visual aids to ‘drive home’ your points.

4) Explain hazards that could arise from certain production/construction methodologies and

possible means of forestalling or reducing such hazards.

5) Initialize the work by starting your subordinates off with the necessary procedures on the

job and allow for continuity from there. Mostly relevant when your direct subordinates

are completely unskilled.

6) Minimize your assumption as regard the basic understanding of your subordinates. Never

assume that they know too much (depending on their educational background and

experience).

7) All presentations made in an attempt to impact knowledge and/or skill should be

simplified as much as possible using the simplest technical terms. This does not

necessarily imply that the common ‘lay-man’s’ terms alone should be used without

reference to the actual technical terms, but that any relatively new or highly grammatical

term should be simplified.

8) Share your personal experiences. “Experience” they say, is the best teacher, share, most

especially those things you’ve learnt on-the-job which are not usually things you find in

the books.

9) Always allow your subordinates to ask questions and give them satisfactory answers in

every instance. Whenever a recurring question is observed from some of your

subordinates, try to collectively re-educate them about the general concept of the

problem.

111

10) Lay emphasis on certain procedures that required sound scientific background and

technical knowledge and if possible refer them to the relative fundamental principles

required.

11) Do not ‘hide’ anything. Your ability to maximally transfer knowledge and skill depends

directly on your ability to explain everything you know satisfactorily.

CONCLUSION

All the principles outlined above can only become effective when the supervisor/foreman,

using his own initiatives, engages the principles on a systematic and consistent basic. They

have to become past-and-parcel of him as there could be need to engage any one, two or more

of these principles at any point in time in order to transfer knowledge and skills to his

subordinates.

14.50 DISCIPLINE AND LEADERSHIP ON SITE.

14.51 INTRODUCTION:

MEANING, PREVENTION AND REMEDIATIONS

In talking about discipline, it is important to realize the meaning of “discipline”, for

often it is confused with punishment. The term “discipline”, refers to an understanding and

acceptance of behavioral limitations which we must all accept in order to live harmoniously

in a social setting. This implies two very important dynamics – an understanding of those

limitations and an acceptance of them as a reasonable limitation to place upon oneself. As a

leader, our responsibility becomes one of both interpreting the types of behaviors which hare

acceptable to us and conducive to good climate, and helping subordinates to see the

importance of accepting those limitations. On the other hand, if leaders do not have necessary

management skills, they will probably perform poorly and be relatively unsuccessful.

According to Kate (1980) management skills are classified into three primary skills namely;

Technical Skills, Human Skills and Conceptual Skills. Here, we shall be concerned with

human skills which are skills that build cooperation within the team being led. Human skills

involve working with attitudes, communication, individuals and groups, and individual

interests; in short, working with people.

112

Basically, as a leader moves from one level to the next, human skills become more

important. The supportive rationale is that as leaders advance in an organization, their task

becomes less involved with the actual production activity or technical areas and they become

more concerned with discipline and guiding the organization as a whole. Human skills,

however, are extremely important to leaders regardless of levels at which they find

themselves, because the common denominator of all management levels is people.

With this sort of understanding of discipline and leadership role in mind, there are

some concrete actions that the leaders can use in order to encourage a site climate that is both

comfortable and productive. These take place on two levels. The first, PREVENTION,

implies that there are certain actions that the leader can do which will prevent misbehavior

from happening. This generally requires a fair amount of organization and forethought on the

part of the leader to accomplish, but is the less stressful of the two types of intervention that

leaders might choose to apply. Weber (1982) describes this approach as the Instructional

Management approach. This approach is based on the premise that carefully designed and

implemented ground rules will prevent many site discipline problems. The second level is

REMEDIATION. This means an action by the leader in response to some inappropriate

worker’s behaviour. This is sometimes called the “brush fire” approach, for unless the leader

is careful, he or she may spend a good portion of the day dealing with behavioral problems

after they occur.

14.60 PREVENTION

1) Establish clear expectations for behaviour which focus on the positive behaviors that

you wish to encourage (that is, what workers should do). We all need to know what

the acceptable parameters for behaviour are in our social interactions. Too often the

site becomes a guessing game. Will the leader get angry if I do this? Is it surprising

that workers TEST leaders by seeing how far they can push misbehavior? They are

trying to establish those limits, by being very upfront in stating what behaviors are

acceptable, the leaders no longer has hidden agenda that the workers must guess at.

This does not mean to imply that the source of these rules must come exclusively

from leaders. Workers are very effective at identifying behaviors that are conducive to

good working environment and will often be more willing to accept rules that they

have generated themselves. However if this latter approach is applied, it is important

for the leader to have thought through the kinds of rules which are acceptable to avoid

unreasonable or irrational rules from becoming site law. According to Evertson

Emmer, Clements, Sanford and Worsham (1984) one of the surest ways to

113

communicate expectations for workers behaviour is through a systematic plan of

ground rules. This system of rules must be taught to workers and this includes:

a) Describing and demonstration of desired behaviour.

b) Rehearsing and practicing the appropriate behaviour and

c) Providing feedback to the workers as to whether they exhibited the desired

behaviour or not.

Through such a planned teaching of ground rules, the likelihood of clearly understood

expectations might be expressed.

2) Think through outcomes for misbehavior which are acceptable to you and follow

through with these outcomes. It is easy to be caught up in the anger of a confrontative

situation and dole out disciplinary measures which is unacceptable. If it really

acceptable to dismiss a worker from the site for not completing a given task. Doesn’t

this just reinforce the behaviour which is being subjected to disciplinary action?

According to Seifert (1983), William Classer suggests that leaders should rather try to

use the natural consequences for unacceptable behaviour. For example, if a worker

misbehaves on the site, he or she can have the site privileges removed for a period of

time. Leaders need to think through the kinds of behaviour problems that can happen

and determine ways that they are comfortable dealing with those problems.

3) Don’t use threats. Workers quickly realize that threats are just that without

consequences. It is important to have acceptable punishments (staying after work, not

going on a no-argumentative manner, and then if the behaviour persists, follow

through with disciplinary action.

4) Develop an understanding of group process. Many behavioural problems are

avoided by a site atmosphere that encourages cooperation. This cooperative behaviour

does not come naturally but must be fostered through discussion of ways in which

groups do or do not work well together by monitoring the group process during

activities to determine where breakdowns in the process are occurring, and by

carefully evaluating with workers after an activity how well they worked and how

well they felt about working in their group. According to Weber (1983) the major

premise underlying the group process approach is based on at least three assumptions:

• the central task of the leader is to establish and maintain effective and

productive site group.

114

• The site group is a social system containing properties common to all social

systems and is characterized by certain conditions that are compatible with those

properties and

• The site management task of the leader is to establish and maintain conducive

working environment.

5) Use site organization to prevent temptations. Much of misbehaviour in a site

can be avoided by a little foresight. Workers don’t enter a working environment with

the same constraints that are common. Hence, they are not as tolerant of

disorganization or confusion with equal vigour. Such as giving brochures that contain

the rules and regulations before expecting the workers to settle on site help greatly in

preventing the kinds of misbehaviours that cause the leaders concern.

6) With potential problems in a positive way before misbehaviour blows up (that is

before time bombs). It is amazing how effective it can be to take a worker who has

been disruptive quietly aside and affirm your value at that worker’s contribution to the

workers. For example, Abdul was involved in a fight in the workshop during lunch

and resumes from lunch with fire in his eyes. The leader takes Abdul quietly to one

side of the workshop as the others are putting on their overall and tells Abdul that he

is sorry that he had been involved in a fight, but it is important to forget that it

happened. If Abdul continues to be very angry and upset, then he won’t be able to

contribute to the work and both the leader and the other workers will miss Abdul’s

contributions.

7) Put the responsibility on the worker. Ask the worker, “how should you be

behaving? Give the worker parameters, but allow the worker the responsibility to

make decisions. “Abdul, find a place in the workshop to put your cigarette so that you

would not be tempted to smoke during working hours” is more effective than “Abdul,

bring that cigarette to me right now”. The former affirms Abdul’s worth as an

individual and as a responsible person while the latter only succeeds in setting up a

confrontative situation in which neither Abdul nor the leader can win. According to

Glasser (1969). “the worker has the responsibility to make the decision from his own

evaluation thus learns responsibility.

8) Don’t frame behaviour as question. The leader is the authority in the site and

does not have to ask the workers’ permission to expect their compliance with the

115

leader’s wishes. Asking “will you please bring your time card over here? Leaves open

the possibility for worker to respond “NO” at which the leader has not left a way out

but a confrontation. By framing behaviour as statements, the leader can always

respond “that wasn’t a question, it is a statement - please bring your time card here”.

14.70 Remediation

1) Deal with the behaviour directly and specifically. Avoid statements such as “I don’t

like the way that you are acting”. This becomes an indictment of the worker than the

particular behaviour. Be specific about the behaviour that is offensive so that the

worker understands what it is that he or she is doing inappropriately. That doesn’t

mean that the worker can’t be asked to identify the behaviour that is inappropriate,

but be sure that when you are finished with your discussion, that the worker clearly

understands what behaviour was not acceptable.

2) Use a time-out corner. A technique used effectively by managers. This is a

place where workers can choose to go when the weight of the world is too much to

handle. Workers in this area are not to be bothered by ANYONE, including the

manager (who may also go to this are if needed). The worker may go to the time-out

corner without feeling that they will be punished. What this effectively was is to put

the responsibility on the worker to decide when he or she is able to work with a

group.

3) Deal with behaviour quietly, and when possible, individually do not set up face-

saving power struggles. Some of us likes to be embarrassed in front of others.

Disciplining a worker in front of peers often leads to a power struggle where the

leader even though that may not be the view that he or she holds. Yet it is important

to “save face” in front of other workmates. This is no win situation. A lot of these

guiding principles really centre on one idea – if we truly care about workers and

express that care willingly and openly, we establish the kind of positive site

environment that prevents many of the inappropriate behaviours from happening.

14.80 SUMMARY

• the discussion points to the conclusion that good discipline is an outcome of

proper organization and leadership, and is a by-product rather than an objective.

Preparedness has been emphasized as an attribute of a site leader or manager.

• Problems in discipline can best be avoided through anticipating them and making

plans for their elimination.

116

• Certain details in the routine of managing, if given close attention, will go far

toward removing the seed of disciplinary troubles, as nicely put by Evicson and

Seefeld (1960) “the most important of all requirements in discipline is that the

leader or manager must at all times be in control”. Therefore, you as the site

leader or manager must always be in control”.

117

WEEK FIFTEEN 15.0 Introduction and definitions

This chapter is very vital to you, who is a beginner in this subject. The ability to grasp and

comprehend the following accounting term will lay a very solid foundation to give you

confidence in building a good career.

15.1 DEFINITION OF SOME ACCOUNTING TERMS

15.11 BOOK-KEEPING: Is the art of recording the financial transactions of a business or an

individual in terms of money, and in set of books in order to obtain necessary information

when needed.

It is the analysis, classification and recording of financial transactions in books of

accounts.

The work of an accountant starts where the book-keeper stops. Book-keeping is a part of

financial accounting.

15.12 FINANCIAL ACCOUNTANT – The American Institute of Certified Public

Accountants (AICPA) defined financial accounting as “the art of recording, classifying and

summarizing in a significant manner and in terms of money, transactions and events which

are, in part at least, of financial character and interpreting the results thereof.”

From the above definition, it is important to note that recording of any financial

transaction is done in money terms, i.e. recording are not done in terms of weight, e.g. Ibs,

oz. kg. e.t.c. But it terms of money: N, $, etc.

15.13 BUSINESS: Is the conduct of legitimate commercial activities to produce and

distribute goods and services in return for profit.

15.14 TRANSACTION: When there is a business deal or piece of commercial activity

between two parties, it is called a transaction. E.g. A buys goods from B. The function of

book keeping as already noted in the definition is to record business or financial

TRANSACTIONS . There are two types of transactions: CASH and CREDIT transactions.

15.15 A CASH TRANSACTION: Is the transaction where goods or services are supplied to

a customer and the MONEY paid at precisely the same time, either by cash or cheque.

15.16 A CREDIT TRANSACTION : Is the transactions where goods or services are

supplied to a customer but the payment is delayed or postponed or deferred until a future

date. The most unusual credit period is one month. Though payments for goods or services

are not made immediately, the recording is still done in terms of money’s worth.

118

15.2 STARTING A BUSINESS

To be engaged in business, one must have property or resources to aid business

transactions.

15.21 ASSETS: Constitute property or resources of a business or an individual. E.g. cash,

goods bought to be sold (stock), bank balance, motor van, machines, building, debtors, land,

e.t.c.

There are basically two types of assets:

a) Fixed assets b) Current or circulating assets

Another type of asset worth mentioning is fictitious assets.

15.22 FIXED ASSETS: Are resources or property of a durable nature, for long-term use

in the business and are not primarily meant for resale or for conversion into cash. E.g.

Land, building, fixtures and fittings, plants and machines, motor vehicles, e.t.c.

15.23 CURRENT ASSETS: Are resources or property which represent cash or are to be

primarily changed into cash and have short life duration as the business continues. E.g.

cash in hand, stock, debtors, cash at bank, e.t.c.

Note: Alternatively, current assets are known as circulating assets. A debtor is one who owes

money. Converted to used to buy

Goods sold for cash

Debtors

Pay

Cash

Pay Cheque Sold to

Diagram 1: Showing current or circulating asset as they change to cash

15.24 PURCHASES: When goods are bought for the purpose of selling to make profit, they

are termed “purchases” account for they are not meant for sale but intended to be

permanently used in the business. However, when a business trades in machines, i.e. buying

and selling of machines, then the purchases of machines for sale in this case, are included in

“purchases” account.

15.25 SALES: When goods for the purpose of selling (i.e. purchases) are sold to make profit,

they are termed “sales”.

CHEQUE BANK

CASH

Debtors

STOCK

119

The sale of a fixed asset intended for permanent use should not be included in “sales”

account.

15.26 STOCK: The current Asset- “Stock”: is the total goods left when sales are made out

the goods purchased. This is what appears in the balance sheet as closing stock.

Therefore, purchase of goods will add to stock while sales of goods are a reduction in

stock.

Also, when customers return goods previously sold out to them to a trader, it is addition to

the stock of the trader. This is known as RETURNS INWARDS in the trader’s record.

And a return of goods previously bought by a trader to his supplier is reduction into the

stock of the trader. This is known as RETURN OUTWARDS in the books of the trader.

Addition to

Stock + Subtraction

From stock

15.27 LIABILITIES : Are debts for which a business or an individual is liable or responsible

to settle arising from past transactions. There are current liabilities and long term liabilities.

Capital is a special form of liability; it is what the business owes the owner.

15.28 CURRENT LIABILITIES : Are debts of which settlements is to be made within a

short period of time, say a month or at most a year. E.g. creditors, rent due, wages due,

over draft, etc.

15.29 LONG TERM LIABILITIES : Are debts of which settlement is to be made after a

long period of time say after a year. E.g. Bank loan, Loan from individuals, Debentures

e.t.c.

15.30 CAPITAL : Is the contribution by the owner in cash or kind to the business or

accumulated by him out of profits ploughed back into the firm. Capital is thus indebtedness

or a liability of the business to the owner. It is the amount due to the owner and owed by the

business.

It is pertinent here for the reader to regard the owner or proprietor as someone separate

from the business. Thus when the owner puts money or any resource (asset) into the business,

ii is regarded as the business owing the owner. In other words it is the owner’s commitment

to the business financially and materially.

15.31 DRAWINGS: When the owner or the proprietor takes any property belonging to the

business (firm) for his private use, the property withdrawn is known as “drawings”. This may

be withdrawal from cash or from purchases or any property. Goods withdrawn by the owner

is charged to his account at cost and purchases account credited.

Purchases & Returns Inwards

STOCK Sales & Return Outwards

120

Thus, two accounts are maintained for the owner viz. capital and drawings accounts.

In recording transactions of the business, student should note that he/she is recording for the

business and not for the owner. This is vital.

15.32 ACCOUNTING EQUATION : When the business is liable to only the owner, the

accounting equation is expressed as total assets equal capital. That means all the assets were

provided by the owner.

This is represented by an equation:

A=C. . . . . . . . . . . . .(ii)

Where A=assets and C=capital

On the other hand where the business is liable to the owner and other external parties, the

accounting equation is expressed as total assets equal owner’s capital (equity) plus liabilities.

That means the owner and other people/ organization provided the total assets.

The equation is represented by:

All the 3 items in the equation are variables, i.e. they are not constant or fixed.

Whenever two of the items are known the other can be calculated by simple addition or

subtraction. For example, Bello started a business with building30, 000, Motor van 20,500,

Cash 6,500, Loan from E. Kind 15,000.

The capital can be calculated because assets and liability (of loans) are given. From the

equation C=L=A, we can deduce that, C=A-L. Therefore, Capitals=Assets (Motor van 20,

500, + Building 30, 000+ Cash 6, 500) - Liability (loan 15, 000) = 42,000.00.

A L C

i.e. 57, 000 - 15, 000 = 42, 000

NOTE: The accounting equation is the expression of the financial position statement, the

balance sheet.

Since capital is a special liability to the firm it is convenient to refer to the ‘C+L’ as the

liabilities side of the equation and ‘A’ as Assets side of the equation.

15.3 DOUBLE ENTRY SYSTEM:

There are two aspects involved in every financial transaction. For example in a single

transaction of a trader selling goods to a customer by cash, the two aspects are:

a) The GIVING of goods (by the trader)

b) The RECEIVING of payment of cash (by the trader).

There is a GIVING and a RECEIVING. This two-fold aspect involved in every

transaction gave rise to double entry system.

121

The system of double entry book-keeping which is believed to have originated in the

fifteenth (15th) century is fundamental to the recording of financial transactions. This dual or

double aspect to every transaction affects assets, capital or liabilities, revenue and expenses.

The double entry system is operated effectively by accounts.

15.4 AN ACCOUNT:

An account records changes of an asset or liability of the business. Thus there are accounts

like: Building’s account (for transactions involving building), Loan-Goodness account (for

transactions involving loan from goodness) Motor van’s account (for transaction involving

motor van) and so on for every asset, liability and for capital. An account will therefore

contain the record of the “life history” of the increase or decrease of an asset or liability.

15.5 FEATURES OF AN ACCOUNT:

Each account has a separate 12 pages or ‘folio’ in a ledger (a book containing various

accounts). The double entry system divides each account into two halves to give an account a

‘T’ shape- this ascertains or indicates that each accounts is capable of RECEIVING and

GIVING .

The left hand side of each account is called the DEBIT side (abbreviated as DR) and

represents the side of account that receives the goods, services or money. To debit (DR) an

account means entering the amount of money (N) of the value of goods or services received

into the account and are termed a debit entry.

The right hand side of an account is called the CREDIT side (abbreviated as CR) and

represents the side of the account, that GIVES goods, services or money. To credit (CR) an

account means entering the amount in money (N) of the value of goods or services given out

of the account and it is termed a credit entry.

Each transaction affects two accounts, one account to be debited and the other to be

credited with the same amount. In other words, if one account has RECEIVED another

account has GIVEN . The general rule is:

DEBIT (DR) or charge the account that RECEIVES.

CREDIT (CR) the account that gives.

Therefore, for every debit entry there must be a corresponding credit entry and vice

versa.

The title of each account is written across the top of the account at the centre.

Example of motor van’s account – Specimen – is shown below:

Motor Van’s A/c

122

Date Details Folio Amount Date Details Folio Amount

Each account (abbreviated as A/c) has columns for date, particulars or details, folio and

amount for both the DR and CR side as shown above. The date columns record1 when (day)

the transaction took place, the particulars or details columns record the name of the account

for which value is received or given. The folio columns record the page of the accounts in the

details columns, where double entry is completed. The amounts columns record the value

given or received in terms of money.

15.6Steps to follow in recording by the double entry system.

Step 1 Identify the two accounts (at least) involved in every transaction.

Step 2 Identify the account receiving and the one giving.

Step 3 Debit the account receiving and credit the account giving.

NOTE: To identify accounts in a statement of transaction always look for names of assets

mentioned or liabilities mentioned in the statement of transaction, also the type of expense

(e.g. rent) or the type of revenue (e.g. sales).

Using accounts we can effect the double entry system with the aid of some transactions.

1st Transaction

On January 1, 19Y6, B. Joe started business and deposited N400, 000 (inherited from his

father) to the business bank account.

NOTE: Here the two accounts involved in the transaction are capital (owner’s A/c) and a

bank A/c. In identifying the account involved in this transaction bank and the owner of the

business (capital) are mentioned in the statement of transaction.

So, Bank A/c is RECEIVING (from capital) Capital A/c ism GIVING (to bank) Applying

the general rule:

DR Bank A/c.

CR Capital A/c.

NOTE: We have followed the 3 steps in recording by the double entry system outline above.

P.g1

123

DR Capital A/c CR

Date Details Folio Amount Date Details Folio Amount

19Y6 N

Jan. 1 Bank 2 400, 000

Pg. 2

DR Capital A/c CR

Date Details Folio Amount Date Details Folio Amount

19Y6 N 19Y6 N

Jan. 1 Capital 1 400, 000 Jan.1 Motor Van 3 250, 000

2nd Transaction

On January 5; Joe bought a Motor Van for N250, 000 by cheque. Here, the two accounts

involved in the transaction are: -

a) Motor Van A/c (RECEIVING from bank) -DR Van

b) Bank A/c (Giving to motor van) -CR Bank

NOTE: We have already opened a bank account so we continue with the same account for all

further transactions involving bank account. We only need to open motor van’s account.

Pg. 3

DR Motor van’s A/c CR

Date Details Folio Amount Date Details Folio Amount

19Y6 N

Jan. 5 Bank 2 250, 000

3rd Transaction

124

On January 9, Joe took loan from Mrs. Goodness in cash N50, 000. The two accounts

involved in this transaction are:

a) Cash Account (RECEIVING from loan Account – Mrs. Goodness): DR cash

b) Loan Account – Mrs. Goodness (GIVING to cash account): CR Loan – Mrs.

Goodness Account.

Pg. 4

DR Loan – Mrs. Goodness A/c CR

Date Details Folio Amount Date Details Folio Amount

19Y6 N

Jan. 9 cash 5 50, 000

Pg. 5

DR Cash A/c CR

Date Details Folio Amount Date Details Folio Amount

19Y6 N

Jan. 9 Loan Goodness 4 50, 000

4th Transaction

On Jan 10, goods were bought for resale for N16, 000 from G. Garba to be paid for at a

later date.

The two accounts involved in this transaction are:

a) Purchases account (RECEIVING from G. Garba): DR G. Garba

b) G. Garba Account – Creditor (GIVING to purchases): CR G. Garba

Pg. 6

DR Purchases A/c CR

Date Details Folio Amount Date Details Folio Amount 19Y6 N Jan. 10 G. Garba 7 16,000

125

Pg. 7 DR G. Garba’s A/c CR Date Details Folio Amount Date Details Folio Amount 19Y6 N Jan. 10 Purchases 6 16, 000 The folio columns have been used assuming that each account is on a separate page as

indicated on them.

Note on the 4th transaction

Where a CREDIT transaction takes place as in the 4th transaction it is necessary to open an

account in the name of the supplier or the customer. Where a cash transaction takes place it

wouldn’t be necessary to have the name of the supplier.

From the transactions above, it is clear that for every DR entry there must be a

corresponding CR entry and vice- versa. This can go on and on to give a systematic recording

of all the financial transactions engaged by an individual, firm or company over a long period

of time.

It is vital to note that, the debit and credit aspects of each transaction must always be

considered alone without anything that has happened previously or that may happen

subsequently. Thus the purchase or sale of goods on credit entry in each party’s books, while

the settlement by cash or cheque subsequently for such goods is a separate transaction which

also necessitates both a debit and a credit entry in each party’s book.

15.7 Double Entry and Accounts

Example 1

Write up the various accounts required in the books of P. Solo to record the following

transactions for the month in March 19Y5.

19Y5

March 1 Started business with N8, 500 cash

March 4 Bought a motor van for N6, 500 cash

March 18 Bought Office Equipment on credit from Equipmech Co. for N2, 500

March 25 Took loan of N4, 00 from Mercy by cash

March 31 Paid Equipmech N2, 500 owing to them by cash.

126

The way in which the two aspects of every transaction is determined and how the general

rule is applied is tabulated below; (This is not necessary when the student is fully grounded in

the understanding of the basic knowledge of the system).

Date Transactions Identification of A/c Double Entry Recording

March 1 started a business with N8, 500 Cash receiving DR cash Cash. Capital giving CR capital March 4 bought motor van N6, 500 by Motor van receiving DR Motor van Cash. Cash giving CR cash March 18 bought office equip on credit from Equipment – receiving DR equipment Equipmech N2, 500 Equipmech – giving CR equipmech March 25 Took loan of N4, 000 from mercy by Cash – receiving DR cash Cash. Loan – mercy – Giving CR Loan – Mercy March 31 Paid equipmech N2, 500 owing to Equipmech – Receiving DR Equipmech Them. Cash – giving CR Cash Double Entry now shown in account form; DR Capital CR 19Y5 N Mar. 1 Cash 8, 500 DR Cash A/c CR 19Y5 N 19Y5 N Mar. 1 Capital 8, 500 Mar. 4 Motor van 6, 500 Mar. 25 Loan – Mercy 4, 000 Mar. 31 Equipmech 2, 500 DR Motor van A/c CR 19Y5 N Mar. 4 Cash 6, 500 DR Office equipment A/c CR 19Y5 N Mar. 1 Equipmech 2,500 DR Equipmech co. A/c CR 19Y5 N 19Y5 N

127

Mar. 31 Cash 2, 500 Mar. 18 Office equipment 2, 500 DR Loan – Mercy A/c CR 19Y5 N Mar. 25 Cash 4,000

15.8 CLASSIFICATION OF ACCOUNTS:

As already mentioned, an account records the changes of an asset or liability of the

business. It is a page in the ledger which records the transactions relevant to the person, asset,

expense or profit named on the heading.

There are three kinds of accounts viz: Personal Accounts, Real accounts and Nominal

accounts. (The last two are called impersonal accounts).

15.81 PERSONAL ACCOUNTS: They are accounts dealing with persons either as an

individual, Mr. Bello, or a firm (Partnership), AB & partners or a company (Alfa ltd. Co) A

company is regarded as a legal person. These personal accounts could be either Creditors or

debtors.

Capital is a special personal account. In the example 1 above, Equipment Co is an

example of personal account.

15.82 IMPERSONAL ACCOUNTS – Are those dealing with things and not persons.

Impersonal accounts are of two types: Real and Nominal accounts.

15.83 Real Accounts – Are those dealing with tangible things i.e. Real things that can be

touched e.g. Building, Machinery Bank, Cash and many Fixed Asset.

Real accounts record transactions of property and material of tangible objects.

15.84 Nominal Accounts – Are those dealing with intangible things i.e. they are existing in

name only but cannot be seen or touched. They are not real. E.g. Rent, Rates, wages,

discounts and many other expense or income account.

Nominal accounts record items of expenses incurred and income received, losses made and

gains obtained. Nominal account deals with expenses and revenue that have been used up and

expired within a giving accounting period.

15.9 Rules for Entering up personal Accounts:

The person who RECEIVES goods, services or money from the business is DEBITED.

The person who GIVES goods services or money to the business is CREDITED.

128

15.10 Rules for entering up Real Accounts:

When the Asset concerned has RECEIVED a portion of the resources of the business i.e.

(increase in value of asset), DEBIT the asset.

When the asset concerned has GIVEN up some of its value in service of the business –

(Decrease in the value of asset or depreciation) CREDIT the asset.

15.11 Rule for Entering up Nominal Accounts

Expenses i.e. losses.

When the Expense Account named has RECEIVED money “in name only” from the

business. E.g. rent receiving money on behalf of the Landlord. DR the Expense A/c involved.

Gains i.e. profit (income)

When the account named has GIVEN money “in name only” to the business. E.g. sale A/c

giving money to the business. CR the A/c involved.

Recording in each class of accounts:

Debit Credit

a) Personal accounts DR Receiver CR Giver

b) Real accounts DR Property acquired CR Property used

c) Nominal accounts DR Expenses/ losses CR Income/ gains

d) Cash accounts DR Receipts CR Payments

NOTE: Cash accounts is under real accounts, it is shown separately because of its

importance.

15.12 DIVISION OF THE LEDGER:

15.12:1 LEDGER: The ledger is the main book of accounts (i.e. it is a book containing all

the various accounts already considered). It has pages (folio) which are numbered.

Each page contains an account. The numbers are written at the right hand corner and are

called folio numbers.

When a firm has relatively few transactions, all entries can be entered in the ledger by one

accounts clerk. Thai is, all the accounts – the personal accounts, the nominal accounts and

real accounts are kept in one ledger. As the firm grows however, the volume of transactions

consequently increases presenting a problem for one clerk to cope with all the work – load

involved. Even if more clerks are engaged the problem is not solved, since they will not all be

able to use the only ledger at the only ledger at the same time.

129

Diagram 4: Showing the division of the ledger.

NOTE: Private Ledger also might be kept for the accounts of the owner of the business to

contain capital account. Drawings account, and trading, profit and loss accounts.

This problem calls for the division of the ledger into different books according to their

specific function or purpose. Viz:

a) SALES LEDGER: This is the ledger for customers’ personal Accounts, called sales

ledger, or debtor’s ledger i.e. all the Debtors Accounts are removed from the main

ledger to the sales ledger.

b) PURCHASES LEDGER: This is the ledger for suppliers Personal Account’s, called

the purchases ledger or creditors’ ledger i.e. all the creditors’ accounts are removed

from the main ledger to this ledger.

Main book of accounts (containing all .types of accounts)

LEDGER

SALES LEDGER

PURCHASES LEDGER

CASH BOOK (LEDGER)

GENERAL LEDGER

Contains customers or debtors personal accounts

Contains suppliers or Creditors Personal Accounts.

Receipts and payments of money – bank and cash accounts.

Containing the remaining accounts, i.e. Revenue, Expenses and other Assets and liabilities Accounts other then Cash, Bank, Debtors, and creditors.

130

c) CASH BOOK : The ledger for the receipt and payments of money of many both by

cash and cheque is called cash book, i.e. the bank and cash accounts are removed

from the main ledger to this ledger.

d) The remaining accounts would be contained in a ledger called a GENERAL LEDGER

or a NOMINAL LEDGER.

These ledgers contain accounts and are pan of the double entry system.

OTHER BOOKS – Subsidiary books:

Before the division of the ledger, the ledger was the main book of accounts. However

transactions were not entered into the ledger directly. Transactions are first entered in the

book called the book of original entry or journal. Thus, there is the ledger (the main book of

accounts) and the journal (the subsidiary book or the book of prime / original entry used in

book keeping.)

Journal simple means diary, for daily records. In other words the journal records

chronologically in diary from all transactions as they occur. The journal records the

transactions first with explanation before they are ‘posted’ to the ledger. When transferring

entry from any book of original entry (subsidiary books) to the ledger accounts it is known as

POSTING.

All cash transactions are first entered into the cash book before and posting to the accounts

concerned in their various Ledgers, thus the cash book is a book of original entry. It is also an

account because it is a pan of the double entry system and a ledger too (containing more than

one account).

With the cash book acting as a hook of original entry for all cash transactions, the journal

became free from recording cash transactions. Journals record credit transactions and other

complicated transactions apart from credit or cash transactions e.g. depreciation, bad debts

e.t.c.

15.13 DIVISION OF THE JOURNAL

As with the ledger, when the business expands and the number of credit transactions

increase the journal would be greatly loaded with entries and the clerk in charge would be

overworked. Division is thus extended to the journal according to functions. The division is

as below.

a) SALES JOURNAL – The journal for the debtor – customers. This records al the

CREDIT sales as they are made daily. It is also known as Sales day book or simply

sales Book.

131

b) PURCHASES JOURNAL – The journal for all the creditors – suppliers. This

records all the CREDIT purchases as they are made daily. It is known as purchases

day book or simply Purchases Book.

c) RETURNS INWARDS JOURNAL – The journal for all the returns by the

customers of the goods previously sold to them. This is also known as Returns

Inwards Book or Sales Returns Book.

d) RETURNS OUTWARD JOURNAL – The journal for all returns to the supplier of

the goods previously bought from them. This is also known as Returns Outwards

Book or Purchases Returns book.

e) GENERAL JOURNAL – The journal for all other transactions apart from cash

transactions and the day books already mentioned.

These journals are not accounts and do not form part of the double entry system.

They are only books of original entry before posting to the various ledgers. They are

considered later in detail.

132