Pb602 operation management chapter 7

PB 602 OPERATION MANAGEMENT

PROJECT MANAGEMENT TECHNIQUES

PN SITI MARIAM BINTI SAMAT

Mohamad Ihsan Hakim Bin Rozali 16BPM12F2004Muhamad Shaiful Nizam Bin Abd Rahman 16BPM12F2003Raja Izzat Muqri Bin Raja Zahari 16DPM11F2033

PERT AND CPM

Program evaluation and review technique and the Critical path method is develop in 1950s to help managers schedule, monitor and control large and complex projects.

Définition PERT

• PERT stands for program évaluation and review technique

• A Project management technique That employs three times estimates for each activity

Definition CPM

• CPM stands for critical path method• A Project management technique That uses only one

time factor per activity

Six basic step for PERT and CPM

1. Define the project and prepare the work breakdown structure2. Develop the relationship among the activities. Decide which

activities must precede and which must follow others.3. Draw the network connecting all the activities4. Assign time and/or cost estimates to each activity5. Compute the longest time path through the network. This is called

critical path.6. Use the network to help plan, schedule, monitor and control the

project

Important of PERT and CPM

Answer the question of:

• When will the entire project be completed?• Which are the noncritical activities?• What is the probability that the project will be completed by a

specific date?• At any particular date, is the project on schedule,behind

schedule or ahead of schedule?• On any given time is the money spend equal to,less than,or

greater than budgeted amount?

Important of PERT and CPM

• Are there enough resources available to finish the project on time?

• If the project is to be finished in a shorter amount of time, what is the best way to accomplish this goal at the least cost?

Program Evaluation and Review

Technique (PERT)

Steps to Develop and Analyze a PERT Network

STEP 1Decompose project into individual job or tasks and

identify each of them.

STEP 2Find out activities or tasks sequence and develop

network.

STEP 3Estimate each activities duration time

STEP 4Obtain expected duration time of each activity

STEP 5Determine each activity time variance

STEP 6Find out the critical path of the network under study.

Step 7Calculate project completion probability on the

specified time (date).

Activity Description Time (weeks)A Build internal components 2B Modify roof and floor 3C Construct collection stack 2D Pour concrete and install frame 4E Build high-temperature burner 4F Install pollution control system 3G Install air pollution device 5H Inspect and test 2

Total Time (weeks) 25

Earliest start (ES) = earliest time at which an activity can start, assuming all predecessors have been completed

Earliest finish (EF) = earliest time at which an activity can be finished

Latest start (LS) = latest time at which an activity can start so as to not delay the completion time of the entire project

Latest finish (LF) = latest time by which an activity has to be finished so as to not delay the completion time of the entire project

A

Activity Name or Symbol

Earliest Start ES

Earliest FinishEF

Latest Start

LS Latest Finish

LF

Activity Duration

2

Forward Pass

Begin at starting event and work forward

Earliest Start Time Rule:

If an activity has only a single immediate predecessor, its ES equals the EF of the predecessor

If an activity has multiple immediate predecessors, its ES is the maximum of all the EF values of its predecessors

ES = Max {EF of all immediate predecessors}

Forward Pass

Begin at starting event and work forward

Earliest Finish Time Rule:

The earliest finish time (EF) of an activity is the sum of its earliest start time (ES) and its activity time

EF = ES + Activity time

Backward PassBegin with the last event and work backwards

Latest Finish Time Rule:

If an activity is an immediate predecessor for just a single activity, its LF equals the LS of the activity that immediately follows it

If an activity is an immediate predecessor to more than one activity, its LF is the minimum of all LS values of all activities that immediately follow it

LF = Min {LS of all immediate following activities}

Backward PassBegin with the last event and work backwards

Latest Start Time Rule:

The latest start time (LS) of an activity is the difference of its latest finish time (LF) and its activity time

LS = LF – Activity time

AON Example

Activity DescriptionImmediate

Predecessors

A Build internal components —

B Modify roof and floor —

C Construct collection stack A

D Pour concrete and install frame A, B

E Build high-temperature burner C

F Install pollution control system C

G Install air pollution device D, E

H Inspect and test F, G

Milwaukee Paper Manufacturing'sActivities and Predecessors

AON Network for Milwaukee Paper

G

E

F

H

CA

Start

DB

Arrows Show Precedence Relationships

Activity Description Times(week)

A Build internal components 2

B Modify roof and floor 3

C Construct collection stack 2

D Pour concrete and install frame

4

E Build high-temperature burner

4

F Install pollution control system

3

G Install air pollution device 5

H Inspect and test 2

Perth diagram for Milwaukee Paper

E

4

F

3

G

5

H

2

4 8 13 15

4

8 13

7

13 15

10 13

8 13

4 8

D

4

3 7

C

2

2 4

B

3

0 3

Start0

0

0

A

2

20

42

84

20

41

00

Example 2 :lisa Sdn Bhd owns a data needed to complete a work on a project in Kulim Kedah Farm. Ask your company Assistant Project Manager to prepare a working paper based on information table

Activities Immediate precedence

Activities

Optimistic Time

(month)

Most Likely Time Pessimistic time

A - 4 5 12

B A 3 4.5 15

C A 2 3 4

D C 6 8 22

E B 4 6 8

F C 3 4 5

G D,E 1.5 3 4.5

H B 5 7 15

I H 3 4 5

J G,I 2 4 6

(I) The time required to complete each activity(II) Construct the PERT network for each activity(III) Count ES,EF,LS, and LF(IV) The longest time to complete the project

i. The optimistic time (a)ii. The pessimistic time(m)iii.The most likely time(b)

t =a+4m+b 6

Activities Immediate precedence

Activities

Optimistic Time

(month)

Most Likely Time

Pessimistic time

Expected time

A - 4 5 12 6

B A 3 4.5 15 6

C A 2 3 4 3

D C 6 8 22 10

E B 4 6 8 6

F C 3 4 5 4

G D,E 1.5 3 4.5 3

H B 5 7 15 8

I H 3 4 5 4

J G,I 2 4 6 4

Answer:Pert diagram and cpm will be show at the whiteboard

Advantages of PERT/CPM

1. Especially useful when scheduling and controlling large projects

2. Straightforward concept and not mathematically complex

3. Graphical networks help highlight relationships among project activities

4. Critical path and slack time analyses help pinpoint activities that need to be closely watched

Advantages of PERT/CPM

5. Project documentation and graphics point out who is responsible for various activities

6. Applicable to a wide variety of projects7. Useful in monitoring not only schedules but

costs as well

1. Project activities have to be clearly defined, independent, and stable in their relationships

2. Precedence relationships must be specified and networked together

3. Time estimates tend to be subjective and are subject to fudging by managers

4. There is an inherent danger of too much emphasis being placed on the longest, or critical, path

Limitations of PERT/CPM