PREPARED BY : NOR AZAH BINTI AZIZ KOLEJ MATRIKULASI TEKNIKAL KEDAH 1 3.3 PROJECT NETWORK DIAGRAM.

PREPARED BY :

NOR AZAH BINTI AZIZ

KOLEJ MATRIKULASI TEKNIKAL KEDAH

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3.3 PROJECT NETWORK

DIAGRAM

OBJECTIVES

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Define Network DiagramPurpose of Network DiagramMethod : Activity On the Node (AON)Identify ES, EF, LS, LF using Forward Pass

Calculation and Backward Pass calculationIdentify Critical PathIdentify Slack Time

INTRODUCTION

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• A PND is a pictorial representation of the sequence in which the project work can be done.

• The activities and its duration are the basic building blocks needed to construct a graphic picture of the project

• Its provide - the earliest time at which work can be begin on every activity that makes up the project- the earliest expected completion date of the project

IMPORTANCE OF ND

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• ND can be used for ;i) Planning : gives a clear graphical picture of

the relationship between project activitiesii) Implementation : when updating the project

file with activity status and estimate to completion data, the ND is then automatically updated and can be printed or viewediii) control : while updated ND will retain the status of all activities, the best graphical report and controlling project work will be Gantt Chart

METHODS

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I) THE ACTIVITY ON THE NODE ( AON)

Basic unit of analysis in ND is the activity Each activity is represented by a

rectangle ( activity node) Arrows represent the

predecessor/successor relationship between activities

Every activity in the project will have its own activity node ( each rectangle)

METHODS

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I) THE ACTIVITY ON THE NODE ( AON)

A

B

C

D

E

F

PDM format of a project network diagram

METHODS

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I) THE ACTIVITY ON THE NODE ( AON)

Dependencies- A dependency is simply a relationship that

exists between pairs of activities- 4 types of activity dependencies

A B FS : A finishes, B start

METHODS

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I) THE ACTIVITY ON THE NODE ( AON)

Dependencies

FF : A finishes, B finishA

B

A

A SS : A start, B start

METHODS

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I) THE ACTIVITY ON THE NODE ( AON)

Dependencies

SF : A starts, B finish

A B

I) THE ACTIVITY ON THE NODE ( AON)

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I) THE ACTIVITY ON THE NODE ( AON)

Forward Pass calculations

Creating an initial project network schedule

A 1

B 3

C 2

D 5

E 2

F 3

Start End

EST, LST, EFT, LFT

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CPM uses the following times for an activity

EST - Early Start time is the earliest time the activity

can beginLST - Late Start Time is the latest time the activity

can begin- still allow the project to be completed on time

EFT - Early Finish Time is the latest time the activity can end

LFT - Late Finish Time is the latest time the activity can end

- still allow the project to be completed on time

Forward Pass calculations13

Backward Pass calculations14

CRITICAL PATH METHOD (CPM)

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An effective way to analyze complex projectsRepresent the critical set of activities to

complete a projectHelp to focus on essential activities which are

critical to run the projectAllows the project manager to concentrate on

important activitiesCP is the longest path on ND and the most

important partAny delays on the CP will lead to delay of the

project

CRITICAL PATH METHOD (CPM)

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FLOAT

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• Also known as slack, total float and path float• Is computed for each task by subtracting EFT

from the LFT( @ the early start from the late start)

• Is the amount of time the task can slip without delaying the project finish date.

• Free float is the amount of time a task can slip without delaying the early start of any taskthat immediately follows it.

Slack Time calculations18

EXAMPLE

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Activity Precursor Duration (week)

A - 7

B A 6

C A 5

D A,B 4

E B,C 3

F D,E 2

1. TABLE 1 shows the activities and the durations required to complete a construction project, including the precursor activity.

Refering to the TABLE 1:i) draw the project network diagram.

ii) state the activities on the critical path.iii) calculate the minimum duration of the project.

20 project network diagram

A

D

C

E

FBSTART END

0 7 7

0 0 7

13 4 17

13 0 17

7 6 13

7 0 13

7 5 12

9 2 14

14 3 16

14 1 17

17 2 19

17 0 19

19 19

19 19

0 0

0 0

activity

ES D EF

LS F LF