Construction Engineering and Management Instructor: Dr. Ayham Jaaron.

Construction Engineering and Management

Instructor:

Dr. Ayham Jaaron

ENGINEERING MANAGEMENT

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Class Rules and Instructor Expectations

•Turn off your cell phone before you get inside the class room.•Be on time and respect deadlines; late homework will not be accepted! •Participate and attend class: be ready and prepare well, that is the key to success! •Quizzes and exams will be closed-book. •Avoid Make-up/incomplete exams!


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Topics1) Management Functions and introduction of construction project planning and scheduling2)Construction scheduling techniques3)Preparation and usage of bar charts4)Preparation and usage of the Critical Path Method (CPM)5)Preparation and usage of Precedence Diagramming Method (PDM)6)Issues relating to determination of activity duration7)Contractual provisions relating to project schedules8)Resource leveling and constraining9)Time cost tradeoff10)Schedule monitoring and updating.11)Communicating schedule12) Project control and earned value Control13) claims, Safety and Quality control


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In order to understand project management, one must begin with the definition of a project. A project can be considered to be any series of activities and tasks that :.

● Have a specific objective to be completed within certain specifications

● Have defined start and end dates

● Have funding limits

● Consume human and nonhuman resources (i.e., money, people, equipment)

● Are multifunctional (i.e., cut across several functional lines)

What is the Project


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OR

‘‘a temporary endeavor undertaken to create a unique product, service, or result’’


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Project Life Cycle


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Five Process group

Project initiation ●Selection of the best project

given resource limits ●Recognizing the benefits of

the project ●Preparation of the documents

to sanction the project ●Assigning of the project

manager

Project planning ●Definition of the work

requirements ●Definition of the quality and

quantity of work ●Definition of the resources

needed ●Scheduling the activities

●Evaluation of the various risks

Project execution ●Negotiating for the

project team members ●Directing and managing

the work ●Working with the team

members to help them improve

Project monitoring and control

●Tracking progress ●Comparing actual outcome

to predicted outcome ●Analyzing variances and

impacts ●Making adjustments

Project closure ●Verifying that all of the work

has been accomplished ●Contractual closure of the

contract ●Financial closure of the charge

numbers ●Administrative closure of the

paper work


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Successful project management can then be defined as having achieved the project objectives:

● Within Time

● Within Cost

● At the desired performance/Technology level

● While utilizing the assigned resources effectively and efficiently

● Accepted by the customer


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What is Project Management Project management is the planning, organizing,

directing, and controlling of company resources for a relatively short-term objective that has been established to complete specific goals and objectives.


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The potential benefits from project management are:

● Identification of functional responsibilities

● Minimizing the need for continuous reporting

● Identification of time limits for scheduling

● Identification of a methodology for trade-off analysis.

● Measurement of accomplishment against plans


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The above definition requires further comment. Classical management is usually considered to have five functions or principles:

● Planning

● Organizing

● Staffing

● Controlling

● Directing


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Planning

– Where the organization wants to be in the future and how to get there.

Organizing

– Follows planning and reflects how theorganization tries to accomplish the plan.

– Involves the assignment of tasks, grouping oftasks into departments, and allocation of resources.


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Leading

– The use of influence to motivate employees toachieve the organization's goals.

– Creating a shared culture and values,communicating goals to employees throughoutthe organization, and infusing employees toperform at a high level.Controlling

– Monitoring employees' activities, determining if the organization is on target toward its goals, and making corrections as necessary


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Conceptual Skill—the ability to see the organization as a whole and the relationship between its parts.

Human Skill—The ability to work with and through people.

Technical Skill—Mastery of specific functions and specialized knowledge

Management Skills


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Project management is designed to manage or control company resources on a given activity, within time, within cost, and within performance. Time, cost, and performance are the constraints on the project.

Constraints of the project


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Resources We have stated that the project manager must control company resources within time, cost, and performance. Most companies have six resources:

● Money

● Manpower

● Equipment

● Facilities

● Materials

● Information/technology


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Actually, the project manager does not control any of these resources directly, except perhaps money (i.e., the project budget).

Resources are controlled by the line managers .

The project manager is responsible for coordinating and integrating activities across multiple, functional lines. The integration activities performed by the project manager include:


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● Integrating the activities necessary to develop a project plan

● Integrating the activities necessary to execute the plan

● Integrating the activities necessary to make changes to the plan


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Project Scheduling Planning, Scheduling,

and Control

1


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Planning and Scheduling

Planning and scheduling are two terms that are often thought of as synonymous

They are not!

Scheduling is just one part of the planning effort.


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Project planning serves as a foundation for several

related functions such as cost estimating, scheduling,and project control.

Project scheduling is the determination of the timing and sequence of operations in the project and their assembly to give the overall completion time


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Planning is the process of determining how a project will be undertaken. It answers the questions:

1“ .What” is going to be done,2“ .how,”

3“ .where,”4 .By “whom”, and

5“ .when” (in general terms: start and finish).

Scheduling deals with “when” on a detailed level… See Figure 1 .


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The Plan

WhatHow much

By whom

where

Why

How

when

Figure 1 . Planning and Scheduling


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The PlanPMI defines project management plan as a ‘‘formal, approved document that defines how the project is executed, monitored and controlled”.

The plan can include elements that has to do with scope, design and alternate designs, cost, time, finance, land, procurement, operations, etc.


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WHY SCHEDUALE PROJECTS ?

1 -To calculate the project completion.

2 -To calculate the start or end of a specific activity.

3-To expose and adjust conflict between trades

or subcontractor.

4 -To predict and calculate the cash flow.

5-To evaluate the effect of changing orders ‘CH . ’


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6 -To improve work efficiency.

7 -To resolve delay claims , this is important in critical path method ‘CPM’ discussed later..

8 -To serve as an effective project control tool.


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The Tripod of Good Scheduling System1.The Human Factor : A proficient scheduler

or scheduling team.

2. The Technology : A good scheduling computer system (software and hardware)

3. The Management : A dynamic, responsive, and supportive management.

If anyone of the above three ‘‘legs’’ is missing, the system will fail.


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Scheduling and project management Planning, scheduling, and project control are extremely important components of project management.project management includes other components :• cost estimating and management,

• procurement,

• project/contract administration,

• quality management,

• and safety management.

These components are all interrelated in different ways.


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Bar (Gantt) Charts

2


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DEFINITION AND INTRODUCTION• A bar chart is ‘‘a graphic representation of

project activities, shown in a time-scaled bar line with no links shown between activities’’

The bar may not indicate continuous work from the start of the activity until its end.

or

Non continuous (dashed) bars are sometimes used to distinguish between real work (solid line) and inactive periods (gaps between solid lines)


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• Before a bar chart can be constructed for a project, the project must be broken into smaller, usually homogeneous components, each of which is called an activity, or a task.

Item ActivityM 10 Mobilization

Bars ( Month or Year )


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ADVANTAGES OF BAR CHARTS

1- Time-scaled

2- Simple to prepare

3- Can be more effective and efficient if CPM based - Still the most popular method

4- Bars can be dashed to indicate work stoppage.

5- Can be loaded with other information (budget, man hours, resources, etc.)


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Bar Charts Loaded with More Info.Such as : budget, man hours and resources .

10 12 7 11 10 9 15

500$

220$

400$

850$

140$ 500$

900$


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DISADVANTAGES OF BAR CHARTS

1- Does not show logic

2- Not practical for projects with too many activities- As a remedy, we can use bar charts to show:

1. A small group of the activities (subset)

2. Summary schedules


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Basic Networks

3


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DEFINITION AND INTRODUCTION

• A network is a logical and chronological graphic representation of the activities (and events) composing a project.

• Network diagrams are the preferred technique for showing activity sequencing.

• Two main formats are the arrow and precedence diagramming methods.


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Two classic formatsAOA: Activity on ArrowAON: Activity on Node

Each task labeled withIdentifier (usually a letter/code)Duration (in std. unit like days)

There are other variations of labeling

There is 1 start & 1 end event

Time goes from left to right


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Arrow Diagramming Method (ADM)

1 .Also called activity-on-arrow (AOA) network diagram or (I-J) method (because activities are defined by the form node, I, and the to node, J)

2 .Activities are represented by arrows.

3 .Nodes or circles are the starting and ending points of activities.

4 .Can only show finish-to-start dependencies.


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i j

(a) Basic Activity

Activity Name

Node (Event) i

j > i

Each activity should have a unique i – j value

Node (Event) j

Basic Logic Patterns for Arrow Diagrams


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2 A

(b) Independent Activities

4 10 B 12

3 A 6 B 9

(c) Dependent Activities


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2

A

(d) A Merge

4

6B 8

(e) A Burst

C

Activity C depends upon the completion of both Activities A & B

8

A6

2B

4C

Activities B and C both depend upon the completion of Activity A


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(f) A Cross

20

18C

16 D14

A12

B

Activities C and D both depend upon the completion of Activities A and B


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ExampleDraw the arrow network for the project given next.

IPA Activity - A

A B

A C

B D

C,D E


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Solution :

10

30

4020 50

C

D

A

B

E


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Dummy activity (fictitious)

* Used to maintain unique numbering of activities.

* Used to complete logic, duration of “0” *The use of dummy to maintain unique

numbering of activities .


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4 10

4 10

11

A

B

A

B

Divide node to correct

Dummy

(a) Incorrect Representation

(b) Correct Representation


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IPA Activity - A

A B

A C

B,C D


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10 3020 40

C

DA

B

Solution :

10

30

4020 50

C

DA

BDummy

Improper solution

proper solution


505050


IPA Activity - A

A B

A C

B D

B,C E

C F


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Solution :

10

30

40

20 60

C

EA

B

Dummy 1

50Dummy 2

D

F


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Removal of Redundant Dummies

A

A

A

A

B

B

B

B

C C

Original Diagram Diagram after removal of redundant dummies

(a)

(b)


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A

A

A

A

C

C

B

C

B B

Original Diagram Diagram after removal of redundant dummies(c)

(d)

B E

C

E

E E


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Immediately Preceding Activity (IPA)

Depends Upon Activity

-----AB

-----A

A, B

ABC

B CA

Redundant

Relationship


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Activity List with Dependencies:

Depends Upon Description Activity

----------A

A, B, CA, B, C

B, C, J, MB, C, D, E, KD, E, F, G, L

--------------------

Site ClearingRemoval of TreesExcavation for FoundationsSite GradingExcavation for Utility TrenchesPlacing formwork & ReinforcementInstalling sewer linesPouring concreteObtain formwork & reinforcing steelObtain sewer linesObtain concreteSteelworker availability

ABCDEFGHJKLM


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Depends Upon Description Activity

----------A

A, B, CA, B, C

B, C, J, MB, C, D, E, KD, E, F, G, L

--------------------

Site ClearingRemoval of TreesExcavation for FoundationsSite GradingExcavation for Utility TrenchesPlacing formwork & ReinforcementInstalling sewer linesPouring concreteObtain formwork & reinforcing steelObtain sewer linesObtain concreteSteelworker availability

ABCDEFGHJKLM

Removing Redundant Relationships:


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AOA Representation

H4040

G4545

C

F

D3535

1515

1010

55B

A

2020

M

2525J

3030

E

L

K


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NODE NETWORKS MTHOD (AON)

a) Independent Activities

10A

10A

20B

20B

Activity number

Activity name

b) Dependent Activities

20B

20B

10A

10A

Link

LinkB depends on A


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30C

30C

10A

10A

20B

20B

40 D40 D

c) A Merge Relationship

C depends on A & BD depends on C

d) A Burst Relationship

20B

20B

30C

30C

40D

40D

10 A10 A

B depends on AC depends on BD depends on B


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e) Start & Finish Dummy Activities

AA

CC

BB

EE

DDAA

StartDummyStart

DummyFinish

DummyFinish

Dummy

CC

BB

EE

DD

6161


IPA Activity - A

A B

A C

B D

C,D E


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Solution :

A E

C

DB


6363


IPA Activity - A

A B

A C

B,C D


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A

C

D

B

Solution : ENGINEERING MANAGEMENT

65656565


IPA Activity - A

A B

A C

B D

B,C E

C F


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Solution :

A PF

C

DB

E

F


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Lags and Leads

In some situations, an activity cannot start until a certain time after the end of its Predecessor.Lag is defined as a minimum waiting period between the finish (or start) of an activity and the start (or finish) of its successor.

Arrow networks cannot accommodate lags. The only solution in such networks is to treat it as a real activity with a real duration, no resources, and a $0 budget.

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Examples

Place Concrete

3

Strips Forms 2

3

A lag in a node network

Place Concrete Strips Forms Cure Concrete

A lag in an arrow network

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The term lead simply means a negative lag. It is seldom used in construction. In simple language: A positive time gap (lag) means ‘‘after’’ and a negative time gap (lead) means ‘‘before.’’

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ENGINEERING MANAGEMENTRecommendations for Proper Node Diagram

Drawing

Incorrect Correct

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A

B A B

A

B

A

BImproper proper

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Improper Proper

73


Improper Proper

74


A

B

C

Improper Proper

A

B

C

PS

(a) Do not start a network with more than one node

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A

B

C

Improper Proper

A

B

C

PF

(a) Do not end a network with more than one node

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The Critical Path Method (CPM)

4

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Suppose you decide with your friend to go in hunting trip .

You must do specific activity such that the trip well be at the right way. The following activity must be done .

Introduction

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From chart you can see that the 3rd activity (preparing the jeep) have the longest period of time any delay with this activity leads to delay in the trip this activity is a “critical activity”

Critical activity : An activity on the critical path any delay on the start or finish of a critical activity will result in a delay in the entire project Critical path : The longest path in a network from start to finish

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Steps Required To Schedule a Project

The preparation of CPM includes the following four steps:

1 -Determine the work activities:The project must be divided into smaller activities or tasks.

The activity shouldn’t be more than 14-20 days (long durations should be avoided)

Use WBS in scheduling by using an order of letters and numbers

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2 -Determine activity duration: Duration = Total Quantity / Crew Productivity The productivity has many sources:

1 .The company 2 .The market

3 .Special books

Note: The scheduler must be aware about the non-working days , such as holydays or rain days, etc……

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3 -Determine the logical relationships:

This step is a technical matter and obtained from the project manager and technical team, and logical relationships shouldn’t confused with constraints

4- Draw the logic network and perform the CPM calculations

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5-Reiew and analyze the schedule:

1 .review the logic

2 .Make sure the activity has the correct predecessor

3 .make sure there is no redundant activity

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6- Implement the schedule: Definition: take the schedule from paper to the execution.

7-Monitor and control the schedule:

Definition: comparing what we planed with what actually done.

8-Revise the database and record feedback.

9-Resource allocation and leveling.(will discuss in chapter 6)

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ExampleDraw the logic network and perform the CPM calculations for the schedule shown next.

Duration IPA Activity 5 - A

8 A B

6 A C

9 B D

6 B,C E

3 C F

1 D,E,F G

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In mathematical terms, the ES for activity j is as follows : ESj =max( EFi )

where (EFi) represents the EF for all preceding activities.

Likewise, the EF time for activity j is as follows :

EF j= ESj + Dur j

where Dur j is the duration of activity j

Forward pass: The process of navigating through a network from start to end and calculating the completion date for the project and the early dates for each activity

Forward pass calculations

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A5

G1

C6

D9

B8

E6

F3

22,23

5,11

5,13

13,22

13,19

11,14

0,5

Solution :

87


In mathematical terms, the late finish LF for activity j is as follows:

(LFj =min(LSk

where (LSk) represents the late start date for all succeeding activities.

Likewise, the LS time for activity j (LS j) is as follows:

LS j= LFj - Dur j

where Dur j is the duration of activity

Backward pass: The process of navigating through a network from end to start and calculating the late dates for each activity. The late dates (along with the early dates) determine the critical activities, the critical path, and the amount of float each activity has.

Backward pass calculations

88


Solution :

A5

G1

C6

D9

B8

E6

F3

22,23

5,11

5,13

13,22

13,19

11,14

0,5

22,23

13,22

19,22

16,22

5,13

10,16

0,5

CPM ( ES = LS , EF = LF , TF = FF = 0)

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ENGINEERING MANAGEMENTFour Types Of Floats

There are several types of float. The simplest and most important type of float is Total Float (TF) Total float (TF): The maximum amount of

time an activity can be delayed from its early start without delaying the entire project.TF = LS – ES or TF = LF - EF orTF = LF - Dur - ES

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Free Float: may be defined as the maximum amount of time an activity can be delayed without delaying the early start of the succeeding activities

FFi = min(ESi+1) - EFi

where min (ESi+1) means the least (i.e., earliest) of the early start dates of succeeding activities

91


In the previous example we can find the free float and total float for each activity as the following :

Activity C’s free float, FF = 11 - 11 = 0 daysAnd Activity C’s total float, TF =16 - 11= 5 days …… and so on.

FF TF LF LS EF ES Duration

Activity

0 0 5 0 5 0 5 A

0 0 13 5 13 5 8 B

0 5 16 10 11 5 6 C

0 0 22 13 22 13 9 D

3 3 22 16 19 13 6 E

8 8 22 19 14 11 3 F

0 0 23 22 23 22 1 G

Critical activity Note : We must always realize that FF ≤ TF

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Interfering float: may be defined as the maximum amount of time an activity can be delayed without delaying the entire project but causing delay to the succeeding activities.

TF = FF - Int. or Int. F = TF - FF

Independent float (Ind. F): we may define it as the maximum amount of time an activity can be delayed without delaying the early start of the succeeding activities and without being affected by the allowable delay of the preceding activities.

Ind. Fi = min(ESi +1 ) – max(LFi-1) – Duri

Note: make sure that Ind. F ≤ FF

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Node Format

Activity Name

Activity ID

Duration

ES EF

LS LF

TF FF

94


Event Times in Arrow Networks

The early event time, TE, is the largest (latest) date obtained to reach an event (going from start to finish).

The late event time, TL, is the smallest (earliest) date obtained to reach an event (going from finish to start).Examples

Perform the CPM calculations, including the event times, for the arrow network shown below.

95


10 30

40

20 60

C

EB 50

D

F

70

A

GH

10

5

7

8

9

4

5

8

d1d2

Arrow network for example

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The preceding logic is similar to that of the forward and backward passes: When you are going forward, pick the largest number. When you are going backward, pick the smallest number.

i jAct. NameDur.

TEi

TLi

TEj

TLj

CPM

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10 30

40

20 60

C

EB 50

D

F

70

A

GH

10

5

7

8

9

4

5

8

d1

d2

10

10

7

0

0

15

10

10

19

19

24

2727

27

(0,10)(0,10)

(5,10)(0,5)

(0,7)(8,15)

(10,18)(11,19)

(10,19)(10,19)

(7,11)(15,19)

(19,24)

(22,27)

(19,27)(19,27)

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Float Calculations From Event Times

Total Float

TFij = TLj - TEi - Tij

Example ( In the previous network )

TF40-50 = TL50 – TE40 – T40-50

= 19 – 7 – 4 = 8

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Free Float

FFij = TEj - TEi – Tij

ExampleFF40-50 = TE50 – TE40 – T40-50

= 19 – 7 – 4 = 8

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ENGINEERING MANAGEMENTInterfering Float

INTFij = TLj – TEj

ExampleINTF40-50 = TL50 – TE50

= 19 – 19 = 0

Independent Float

INDFij= TEj – TLi - Tij

ExampleINDF40-50 = TE50 – TL40 – T40-50

= 19 – 15 – 4 = 0

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Summary

i jTTEi

TLi

TEj

TLj

Float Direction TF

FF

Int. F

Ind. F

102


Definitions Activity, or task: A basic unit of work as part of the total project that is easily measured and controlled. It is time- and resource consuming.

Backward pass: The process of navigating through a network from end to start and calculating the late dates for each activity. The late dates (along with the early dates) determine the critical activities, the critical path, and the amount of float each activity has.

Critical activity: An activity on the critical path. Any delay in the start or finish of a critical activity will result in a delay in the entire project.

Critical path: The longest path in a network, from start to finish, including lags and constraints.

.

103


Early dates: The early start date and early finish date of an activity.

Early finish (EF): The earliest date on which an activity can finish within project constraints.

Early start (ES): The earliest date on which an activity can start within project constraints.

Event: A point in time marking a start or an end of an activity. In contrast to an activity, an event does not consume time or resources.

Forward pass: The process of navigating through a network from start to end and calculating the completion date for the project and the early dates for each activity.

Late dates: The late start date and late finish date of an activity.

Late finish (LF): The latest date on which an activity can finish without extending the project duration.

Late start (LS): The latest date on which an activity can start without extending the project duration.

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Precedence Diagram

5

105


The Four Types Relationships

Activities represented by nodes and links that allow the use of four relationships:

1) Finish to Start – FS

2) Start to Finish – SF

3) Finish to Finish – FF

4) Start to Start – SS

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Finish to Start (FS) Relationship. The traditional relationship between

activities .

.Implies that the preceding activity must finish before the succeeding activities can start.

.Example: the plaster must be finished before the tile can start .

Plaster Tile

107


Star to Finish (SF) Relationship

.Appear illogical or irrational.

.Typically used with delay time OR LAG.

.The following examples proofs that its logical .

steelreinforcement

Erect formwork

Order concrete

SF

Pour concrete

5

108


Finish to Finish (FF) Relationship

• Both activities must finish at the same time.

• Can be used where activities can overlap to a certain limit. Erect

scaffoldingRemove Old paint

sanding

painting inspectDismantle scaffolding

FF/1

FF/2

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Start to Start (SS) Relationship

• This method is uncommon and non exists in project construction .

Spread groutClean surface

Set tile

SS

Clean floor area

110


Advantages of using Precedence Diagram

1. No dummy activities are required.

2. A single number can be assigned to identify each activity.

3. Analytical solution is simpler.

111


Calculation

1) forward calculations

EF = ES + D

Calculate the Lag LAGAB = ESB – EFA

Calculate the Free Float

FF = Min. (LAG)

112


2) Backward calculations

For the last task LF=EF , if no information deny that.

LS=LF-D

Calculate Total Float

TF = LS – ES OR LF – EF

TFi = Min (lag ij + TFj )

Determine the Critical Path

113

ENGINEERING MANAGEMENTExample

113Dur. E

S E

F FF TF LF

LS

A1 1

2002

1

B

9 2

110011

2

D

5 11

160016

11 4 16

200020

16 1 20

210021

20

F H

C

5 5

10307

2

E

4 10

143011

7 6 14

203317

11

G

54 3

1) Forward pass calculations 4) Backward pass calculations

2) Calculate the Lag ( LAGAB = ESB – EFA)

0

0 0 0 0

0 0

3) Calculate the Free Float (FF) FF = min.( LAG)

5) Calculate total Float (TF = LS – ES OR LF – EF)

114


114Dur. E

S E

F FF TF LF

LS

A

1 1

2002

1

B

9 2

110011

2

D

5 11

160016

11 4 16

200020

16 1 20

210021

20

F H

C

5 5

10307

2

E

4 10

143011

7 6 14

203317

11

G

54 3

6) Determine the Critical Path

0

0 0 0 0

0 0

The critical path passes through the critical activities where TF = 0

115

Resource Allocation and Resource Leveling

6

116


CATEGORIES OF RESOURCES

Labor

Materials

Equipment's.

117

Schedule Updating and Project Control

7

118

Schedule Updating and Project Control The most important use of schedules is project control : the scheduler compares actual performance with baseline performance.

What is Project Control Project control comprises the following continuous process

1. monitoring work progress .

2.comparing it with the baseline schedule and budget.

3.finding any deviations .

4.taking corrective actions.


119

Schedule updating

Schedule updating is just one part of the project control process.

Schedule updating must reflect

Actual work , and involves change orders (CO) .


Construction Engineering and Management Instructor: Dr. Ayham Jaaron.

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Transcript of Construction Engineering and Management Instructor: Dr. Ayham Jaaron.