Grade 4: OR Section Term 2 Section 6 Project Scheduling: PERT/CPM (1) Youtube: https://youtu.be/nmVNR_oBeQ4

1. By:
Zakaria Elsayed Hasaneen
Teaching Assistant at Faculty of Commerce
Accounting Department (English Section)
Kafrelsheikh University
OR
Section (6)
Project Scheduling: PERT/CPM
Grade 4 –Term 2
Zakaria Hasaneen
Zakaria Hasaneen
Zakaria Hasaneen

2. Activity A B C D E F G
Immediate
Predecessor
-- -- A A,B D C,E E
Expected time 7 9 12 8 9 6 5

3. REQUIRED:
1. Construct a project network
2. Perform Forward and backward passes
3. Determine project completion time
4. Calculate slack values
5. State the critical path

4. A ES EF
t LS LF
Node Convention
A here is the activity being described
t represents the expected activity duration or time.
ES is the earliest time the activity can start
EF is the earliest finish time
LS is the latest start time
LF is the latest finish time without extending the minimum
completion time of the project.

5. sketch
Activity A B C D E F G
Immediate
Predecessor
-- -- A A,B D C,E E
Expected
time
7 9 12 8 9 6 5

6. 1

7. Activity A B C D E F G
Immediate Predecessor -- -- A A,B D C,E E
Expected time 7 9 12 8 9 6 5

9. Activity A B C D E F G
Immediate Predecessor -- -- A A,B D C,E E
Expected time 7 9 12 8 9 6 5

10. Slack for an activity is defined as how
long the activity can be delayed without
extending or increasing the project
completion time.
And it is calculated as
LS – ES or LF – EF
critical path

11. So the slack for A will be:
2 minus 0 or 9 minus 7. Which will be 2.

13. The slack for B will then be 0, for C it will be 7, for D 0, for E 0, for F 0, and for G1

14. So, for example activity C can begin anytime between week 7 and 14 and it
can finish anytime between week 19 and 26.
Thus C can be delayed for up to 7 weeks and the project will still be
completed in week 32.

15. Activities, B, D, E, and F on the other hand cannot be delayed at all without
extending the project’s completion time.
So, for example if D is delayed by 2 weeks, then the project completion time
will be extended
by 2 weeks as well, from 32 to 34.

16. The activities with 0 slack are called critical activities.
And they form the critical path which is the longest path in the network
So ,the critical path here is B-D-E-F.