Network-1 [Compatibility Mode]

8/2/2019 Network-1 [Compatibility Mode]

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y ro ec ann ng an c e u ng s requ re

1. Define the work to be performed2. Develop more realistic schedules and cost estimates based on resources planned to perform the work. . , cost, and technical performance objectives.4. Identify those areas developing potential delays or cost over runs, in time to permit corrective action.



Methods of Planning and Scheduling

Bar Chart Milestone Chart Network Diagrams:

1. CPM 2. PERT



•

jobs to be done and the time taken to .

• Chart consists

of

two

axes,

the

horizontal

axis

complete the jobs and the vertical axis

. • The preparation of Gantt chart follows the

ana ys s.



Sr. No.Sr. No. OperationsOperations

WeeksWeeks % Completion% Completion

11 22 33 44 55 66 77 88 99 1010

11

SITESITE100%100%

100%100%

33 SUBGRADESUBGRADE 40%40%

Actual

44BASEBASE

COURSECOURSE0%0%

55 PAVEMENTPAVEMENT 0%0%



LIMITATIONS OF BAR CHARTS

• activities

• It does not show uncertainties involved in the wor .



• .

• Milestones are key events that occur during e execu on o e pro ec .

• These are identifiable events whose occurrences can be monitored as indicators of progress of the project.





• PDM NETWORK:-

. 2. FINISH TO FINISH (FF)3. 4. FINISH

TO

START

(FS)



PDM NETWORK CONCEPT:-



Project Network

• e wor ana ys s s e genera name g ven o cer a n spec c ec n ques w c canbe used for the planning, management and control of projects

Use of nodes and arrows

• Arrows An arrow leads from tail to head directionally

– Indicate ACTIVITY, a time consuming effort that is required to perform a part ofthe work.

• Nodes A node is represented by a circle

- Indicate EVENT, a point in time where one or more activities start and/or finish.

• Activity – as or a cer a n amoun o wor requ re n e pro ec

– Requires time to complete

– Represented by an arrow

• ummy c v y – Indicates only precedence relationships

– Does not require any time of effort



Project Network

• Event

– Signals the beginning or ending of an activity

–

– Represented by a circle (node)• Network

– ows e sequen a re a ons ps among ac v es us ng no es anarrows

Activity-on-node (AON)

nodes represent activities, and arrows show precedence relationships

Activity-on-arrow (AOA)

arrows represent act v t es an no es are events or po nts n t me



AOA Project Network for House

1

1

2 0

33 2 3 1 1

Lay foundation Dummy

Finishwork

Buildhouse

4

5 6

7

1

Design house

and obtainfinancing

Order and

receivematerials

Selectcarpet

Selectpaint

AON Project Network for House

2

2

4

3

Build house

Finish work

13

3 6

1Start

Design house and

darla/smbs/vit 12

11

Order and receive

materials Select paint

Select carpet



Situations in network diagramB

C

A must finish before either B or C can start

B

C both A and B must finish before C can start

CA

both A and B must finish before either of C or D can

DB

AB

DummyA must finish before B can start

both A and C must finish before D can start

C

D







Example





EXAMPLE

Activity Immd. Predecessor Duration

A - 3

C B 2

D B 3E C 4

F D 1

G A 4

H G 3

I E,F,H 2



AOA Example



CPM

• It is a deterministic method.

of various activities in a project is assumed to.

• Each arrow represents an activity in the project.

point of the activity & the head represents the

.



Critical Path

• “The specific set of sequential tasks upon whiche pro ec comp e on a e epen s

– or “the longest full path”

• All projects have a Critical Path.



DIFFERENT WAYS OF REPORTING AN

ACTIVITY IN PDM NETWORK DIAGRAM



Example

Activity Immd. Predecessor Duration (days)

A - 30

B A 60

C A 45

E B 60

F C 15

G E 30

H D,F,G 0



Example Step 1



Forward Pass

• To determine early start (ES) and early finishmes or eac as

• Work from left to right

• Adding times in each path

• ,the next task is the largest of preceding EF



Example Step 2



Backward Pass

• To determine the last finish (LF) and last

• Start at the end node

• Compute the bottom pair of numbers

’• u uearliest start time



Example Step 3



Example Step 4



• Draw the CPM network

• Analyze the paths through the network

– Compute the activity’s float

float = LS - ES = LF - EF – Float is the maximum amount of time that this activity can be

delay in its completion before it becomes a critical activity,i.e., delays completion of the project

• Find the critical path is that the sequence of activities andevents where there is no “slack” i.e.. Zero slack

– Longest path through a network

• Find the project duration is minimum project completion time



CPM Example:

• CPM Network

f, 15f, 15f, 15f, 15

a, 6a, 6a, 6a, 6g, 17g, 17g, 17g, 17 h, 9h, 9h, 9h, 9

i, 6i, 6i, 6i, 6

,,,,

d, 13d, 13d, 13d, 13 j, 12 j, 12 j, 12 j, 12

c, 5c, 5c, 5c, 5

e, 9e, 9e, 9e, 9



CPM Example

• ES and EF Times



CPM Example

• ES and EF Times

C



CPM Example

• ES and EF Times



CPM Example

• LS and LF Times

C



CPM Example

• LS and LF Times



• Float



CPM Example

• Critical Path f, 15f, 15f, 15f, 15

a, 6a, 6a, 6a, 6 g, 17g, 17g, 17g, 17 h, 9h, 9h, 9h, 9

b, 8b, 8b, 8b, 8

, 6, 6, 6, 6

d, 13d, 13d, 13d, 13 j, 12 j, 12 j, 12 j, 12

c, 5c, 5c, 5c, 5

e, 9e, 9e, 9e, 9



Network Diagrams

• Advantages –

– Reveal interdependencies not shown in other techniques – Ability to calculate critical path

– Ability to perform “what if” exercises

• Disadvantages –

• You need to incorporate this yourself (Resource Dependencies)when determining the “real” Critical Path

– cu o o ow on arge pro ec s

Documents

Network-1 [Compatibility Mode]