Pb602 operation management chapter 7
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Transcript of 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