PROCESS SCHEDULING: PERT-CPM
Module 4 - Case
PROCESS SCHEDULING: PERT-CPM
Part I
Calculate the expected time (hours, days, weeks, or whatever) for the following tasks. Report the time to the next highest whole number.
|
Task |
Optimistic (shortest) Time |
Most Likely Time |
Pessimistic (longest) Time |
Expected Time (answer) |
|
A |
3 |
5 |
7 |
|
|
B |
10 |
15 |
20 |
|
|
C |
4 |
5 |
6 |
|
|
D |
27 |
45 |
90 |
|
|
E |
8 |
9 |
12 |
|
|
F |
81 |
93 |
98 |
|
Part II
|
Each of these CPM diagrams corresponds to one of the task lists given below. Match them. Ex. A:#, B:#, etc. Symbols: START
END
|
A.
|
B.
|
|
C.
|
D.
|
E.
|
Part III
Part IV
Estimated and crash costs for each task are shown in the table below.
Answer the questions below the table.
|
Version 1 |
|
Original Estimates |
|
Crash Estimates |
|
Crash Differentials |
|
|
Task
(T) |
CP
* |
Est. Time, weeks (ET) |
Est. cost, $1000, (EC) |
Crash Time, weeks (CT) |
Crash Cost, $1000 (CC) |
Time saved
(ET-CT) |
Extra cost
(CC-EC) |
|
A |
* |
5 |
10 |
4 |
12 |
|
|
|
B |
* |
7 |
15 |
5 |
17 |
|
|
|
C |
|
5 |
8 |
3 |
12 |
|
|
|
D |
* |
6 |
6 |
5 |
8 |
|
|
|
E |
* |
9 |
12 |
8 |
15 |
|
|
|
F |
|
4 |
16 |
2 |
20 |
|
|
|
G |
* |
5 |
20 |
2 |
21 |
|
|
|
(End) |
|
- |
|
|
|
|
|
CP=Critical Path. If task is on CP, then *; otherwise blank.
1 Fill in the blank cells under Crash Differentials.
2 Instead of the scheduled 7 weeks, Task B took 9 weeks. Which task or tasks should be crashed to make up the lost time, at minimum cost? Explain.
Assignment Expectations
1 There are no page limits. Write what you need to write, neither more nor less. Make each sentence count! (Having said that; it’s unlikely that one page would be enough, and very likely that eight pages would be too much.)
2 Ensure that your answer reflects your detailed understanding of the theory and techniques taught in this module.
References and citations are required. This requirement can be satisfied by citing the module Home page.