1

Nature and classification of construction works

Construction works include all types of predominantly civil engineering and building works, both large and small. They can be classified in three groups as follow:

Light construction Includes works with light structural members and

consequent light foundations. Heavy plants and equipments are not used.

They comprise: residential and commercial buildings, schools, villages and city roads, small water supply and sewerage systems etc.

Construction classification Cont.

Heavy construction

Heavy structural members on massive foundations requiring heavy machinery and equipments, large quantity of materials, labour and finances for their construction, e.g. tunnels, bridges, highways, railways, irrigation works etc

Industrial construction

Construction works related to industries involving specialized equipments and intricate installations, requiring special know how and skills, e.g. oil refineries, steel mills, fertilizers, chemical plants etc.

2

Whether category of the above types, its construction goes through a lifecycle of the following stages:

A: Conception many works originate due to the entrepreneurial efforts

of individuals, but others are a result of demands to satisfy social and public needs.

The idea be promoted with the user agencies to generate sufficient interest for its further consideration anconceived by an individual or a group often needs to development.

3

B: Study and evaluation

preliminary survey and rough estimates are prepared and feasibility studies might be carried out to establish the economic viability of or the social utility of the project before the proposal is finally accepted.

4

C: Design

At this stage drawings and estimates are prepared. Field investigations and surveys are carried out for the purposes of, and the site and alignment finalized.

The acquisition of land and the approval from land authority also take place simultaneously. The economies that can be effected in the cost of a project depend mainly on a decisions taken at the design stage or the basis of site investigations and other related data.

D: Contract (procurement)

The usual method of getting work done is by awarding contract at the best terms available. The contract stage involves preparations for calling tenders, their evaluation, and the final award of work to the selected contractor.

5

E: Construction

Actual work is executed as per design. Variations in site conditions and in other factors from these presumed at the design stage require continue re-assessment of the situation so as to evolve fresh solution to the problems encountered. On completion, the work is handled over to the promoter for its use or operation. continuous interaction between construction & design stage is necessary for solving any problem that might occur.

F: Utilization and maintenance

when the construction is put into actual use, its performance as well as the nature and extent of maintenance and repairs provide a valuable feedback for use in the development of new projects of a similar nature.

6

Project delivery system

Despite other methods of project delivery systems, In Tanzania, construction projects are mostly performed through tradition system on which client procures a contractor to construct the building and consultant to design and supervise the construction works.

For a project to be full accomplished, client have contractual relationships with both the consultant and the contractor, while the later, consultant and contractor exercise a mere relationships, see the bolded and the dashed lines, Figure 1.1.

7

8

Client

Consulting party Contractor

Figure 1.1: Contractual relationships

Non contractual

Contractual

A project

Definition: a project is an endeavour mainly with the following features: (i) objectives to be met (ii) has start and end date (iii) consume resources and (iv) unique features

Therefore, three contracting parties in Figure 1.1 are responsible to deal with the efforts for managing the four outlined features of the project. And we have seen three different classifications of the projects in the introduction section. Now, the question is how?

Assignment:

Outline the roles/responsibilities of each of the three contracting parties that are outlined in Figure 1.1

9

Management functions or elements and application in construction

Management of what? The term has been derived from the act of manage! – SEE FIGURE 1.2

The aims of management in construction work are to facilitate the execution of work in a planned and efficient manner as per design and specifications within the prescribed time limit and within the greatest possible economy in expenditure.

The term management can reflect three terminologies – efficient, effectiveness and adaptability. This shows the know how and affording the following four aspects: processes involved, activities/tasks involved, resources involved, methods involved and the outputs required, with justifications of relationships.

10

11

cp

cp

cp

ConsultantConsultant

ClientClient

ContractorContractor

CPCP

cp

cpcp

cp

cpcp

cp

cp

cp

cp

cp

cp

cp

Figure 1.2: Relationships between contracting parties and the projects’ roles

r

r

r

The management function for achieving the above mentioned goals are outlined:

Planning

The management function of deciding what to do, when to do it, and how. It has the thrust of forecasting issues or tasks ahead of time.

The planner relies on sound judgment based on knowledge and experience as well as the mathematical or statistical methods.

12

In planning construction works, various alternative methods of tackling the work are studied and decision are taken not only about works as a whole, but for each part or section of the work regarding time of inception and completion: labour, materials, machines and finance needed and arrangements to be made for the provision of construction facilities from time to time.

13

Plans also takes care of the likely uncertainties in execution due to various unpredictable factors, such as the weather, difficulties in the procurement of materials in short supply, price fluctuations, absenteeism of labour due to festivals and illness etc. for example in an execution of the job, planner decides whether a job will be done manually or by using machine. He then fixes the starting time, taking into consideration, amongst other factors, the season so that either the work is finished before the rains started to avoid flooding and consequent stoppage of the work

 The time likely to be taken in completing the earth work and the labours required are decided after calculating the volume of earth work involved and determining the output of each labour.

14

The number of pick-axes, shovels and baskets needed can also be worked out, after knowing the number of labours to be engaged. If the excavation is a rocky area, the requirement of blasting and rock cutting would have to be worked out.

 If the work is carried out mechanically, the type of machine and facilities for repair and maintenance would also have to be considered. 

Planning is difficult and expensive. Difficult because it requires forecast of future environments and events, expensive since it ties up significant number of highly paid senior executives.

15

Advantages of planning

Important decisions are taken un-hurriedly, using all the data available and considering all possible options

The firm is compelled to look ahead; thus, possibly avoiding foreseeable pitfalls

Departmental representatives are forced to meet and discuss common problems

The feasibility of objectives are studied in depth

Inefficient and duplicated efforts may be identified and thrown away

Resource deficiencies may be identified and balanced

16

Principles of planning

The plan should be as detailed as expenditure constraints allow

Plans should not extend too far into the future; accurate prediction of the distant future is simple impossible

All alternative courses of action should be considered

Site effects and implications of the actions envisaged should be examined

Instructions to individuals and departments must be incorporated into the plan

Plans should be concise and easy to understand.

Summary

Planning effort seeks what to do, when to do it, and how.

17

Organization

Organization can be viewed in two perspectives, at the firm or at the work’s patterns.

Organization as a firm results from a combination of people who work within the boundaries of their mixed & balanced skills’ strengths vs weaknesses to achieve a common goal.

“It is a system of consciously coordinated activities or efforts of two or more persons”..

Organizations can also be thought as “social entities that are goal directed, deliberately structured activity systems with a permeable boundary”.

18

Organizations exist because no one individual can successful cope, either mentally or physically, with all the various demands for skills, experience, knowledge and ability that are required when, for example, a large construction project is to be undertaken.

These people contribute one part of the total collective expertise that is required to achieve a common objective.

The process of breaking down the work into small tasks, then to be carried out by groups of people/ by individuals who have specialized skills and knowledge is known as the division of labour.

 Organization operates as a system, either closed or open system. A System is an interrelated set of elements functioning as a whole wherein one part necessarily has an effect on the others.

19

We focus on an organization as ‘an open system’

An open system is one in which the system has free interaction with the environment within which it exists.

It must be capable of maintaining its capability to act throughout, regardless of any changes that may take place in the environment. The environment is generally very wide –ranging and will consist of all those influences that can act on an organization.

The organization would be composed of the following factors, legal requirements, technological constraint, political structure, sociological considerations, and education limitations and so on.

20

In the construction context, any aspect of the environment in which the project is being constructed, that can affect the total process is included. The interaction with its environment may take the form of an exchange of information or materials in order to create some form of finished product as a result of the transformation or conversion process being undertaken by the organization.

Organization as the work patternsIt can be referred to as the verb ‘ORGANIZE’, with the four perspectives as outlined

below:

1. Create in a manner of relationships or some kind of a logical manner

2. Cause to be structured or ordered or operating according to some principle or ideas

3. Planed and directed and linked

4. Arrange by systematic planning and united effort

21

Scheduling

A schedule or timetable is a basic time management tool consisting of a list of times at which possible tasks, events, or actions are intended to take place, or a sequence tool in the chronological order in which such things are intended to take place.

 The process of creating a schedule - deciding how to order the tasks and how to commit resources between the variety of possible tasks - is called scheduling, and a person responsible for making a particular schedule may be called a scheduler.

  Making and following schedules is a fundamental human activity, and learning to do these things effectively is one of the most basic life skills. There are a wide variety of situations in which schedules are necessary, or at least useful.

22

Schedules are useful for both short periods, such as a daily or weekly schedule, and for long term planning with respect to periods of several months or years. They are often made using a calendar, where the person making the schedule can note the dates and times at which various events are planned to occur.

  Schedules that do not set forth specific times for events to occur may instead list an expected order in which events either can or must take place.

Project management scheduling

In project management, a formal schedule will often be created as an initial step in carrying out a specific project, such as the construction of a building, development of a product, or launch of a program.

23

Establishing a project management schedule involves listing milestones, activities, and deliverables with intended start and finish dates, of which the scheduling of employees may be an element.

Milestones are an important dates at a glance – where certain activity/task must be achieved, giving room for the other one to proceed

A production process schedule is used for the planning of the production or the operation, while a resource schedule aids in the logistical planning for sharing resources among several activities.

24

In such cases, a schedule "is obtained by estimating the duration of each task and noting any dependencies amongst those tasks".

Dependencies are the tasks that must be completed in order to make other tasks possible, such as renting a truck before loading materials on the truck (since nothing can be loaded until the truck is available for things to be loaded on).

Scheduling of projects, therefore, requires the identification of all of the tasks necessary to complete the project, and the earliest time at which each task can be completed. In creating a schedule, a certain amount of time is usually set aside as a contingency/buffer against unforeseen days. This time is called scheduling variance, or float, and is a core concept for the critical path method.

25

Implementation

When works are planned organized and scheduled, what comes next is the implementation.

It involves putting plans into action using the planned, organized and scheduled resources against the optimal method(s) selected

Commit resources into events/operative issues

Excel efforts into seeing plans and effecting it into actions

Do or engage with the job physically

Put things or a product to happen

26

Controlling

A process of monitoring performance and taking action to ensure achievement of the desired results.

Sees to it that the right things happen, in the right ways, and at the right time.

Done well, it ensures that the overall directions of individuals and groups are consistent with short and long range plans.

It helps ensure that objectives and accomplishments are consistent with one another throughout an operative efforts of within the firm.

27

28

It helps maintain compliance with essential organizational rules and policies.

Establish objectives and standards.

Measure actual performance.

Compare results with objectives and standards.

Take necessary action.

29

The control process begins with planning and the establishment of performance objectives.

Performance objectives are defined and the standards for measuring them are set.

There are two types of standards:

Input Standards - measures work efforts that go into a performance task – what is the link between the inputs used vs method used and the output delivered?

Output Standards - measures performance results in terms of quantity, quality, cost, or time.

30

Measuring Actual Performance

Measurements must be accurate enough to spot deviations or variances between what really occurs and what is most desired.

Without measurement, effective control is not possible.

31

Comparing Results with Objectives and Standards

The comparison of actual performance with desired performance establishes the need for action.

Ways of making such comparisons include:

Historical / Relative / Engineering

Benchmarking

32

Taking Corrective Action

Taking any action necessary to correct or improve things.

Management-by-Exception - focuses managerial attention on substantial differences between actual and desired performance.

33

Taking Corrective Action

Management-by Exception can save the managers time, energy, and other resources, and concentrates efforts on areas showing the greatest need.

There are two types of exceptions:

•Problems - below standard

•Opportunities - above standard

34

Effective Controls

The Best Controls in Organizations are:

Strategic and results oriented

Understandable

Encourage self-control

Timely oriented

Positive in nature

Fair and objective

Flexible

35

Types of Control

Preliminary

Sometimes called the feedforward controls, they are accomplished before a work activity begins.

They make sure that proper directions are set and that the right resources are available to accomplish them.

36

Types of Control

Concurrent

Focus on what happens during the work process. Sometimes called steering controls, they monitor ongoing operations and activities to make sure that things are being done correctly.

37

Types of Control

Post-action

Sometimes called feedback controls, they take place after an action is completed. They focus on end results, as opposed to inputs and concurrent - this type of control may only help to guide future efforts, but he current one would already been interfered.

38

Types of Controls

Managers have two broad options with respect to control.

They can rely on people to exercise self-control (internal) over their own behavior.

Alternatively, managers can take direct action (external) to control the behavior of others.

39

Types of Control

Internal Controls

Allows motivated individuals to exercise self-control in fulfilling job expectations.

The potential for self-control is enhanced when capable people have clear performance objectives and proper resource support.

External Controls

It occurs through personal supervision and the use of formal administrative systems.

Performance appraisal systems, compensation and benefit systems, employee discipline systems, and management-by-objectives.

40

Organizational Control Systems

Managing processes in organizations Strategy and objectives Policies and procedures Selection and training Performance appraisal Job design and work structures Performance norms, and both

individual and organization culture