Question 1: A network consists of the activities in the following list. Times are given in weeks.
|
Activity |
Preceding |
Time |
|
A |
-- |
8 |
|
B |
-- |
3 |
|
C |
A |
7 |
|
D |
A, B |
3 |
|
E |
C |
4 |
|
F |
D |
6 |
a. Draw the network diagram.
b. Calculate the ES, EF, LS, LF, and Slack for each activity.
|
Task |
Early Start |
Early Finish |
Late Start |
Late Finish |
Slack |
|
A |
|
|
|
|
|
|
B |
|
|
|
|
|
|
C |
|
|
|
|
|
|
D |
|
|
|
|
|
|
E |
|
|
|
|
|
|
F |
|
|
|
|
|
c. What is project completion time?
Question 2: A partially solved PERT problem is detailed in the table below. Times are given in weeks.
|
Activity |
Preceding |
Optimistic Time |
Probable Time |
Pessimistic Time |
Expected Time |
Variance |
|
A |
-- |
7 |
9 |
14 |
|
1.361 |
|
B |
A |
2 |
2 |
8 |
|
0 |
|
C |
A |
8 |
12 |
16 |
|
0 |
|
D |
A |
3 |
5 |
10 |
|
1.361 |
|
E |
B |
4 |
6 |
8 |
|
0 |
|
F |
B |
6 |
8 |
10 |
|
0 |
|
G |
C, F |
2 |
3 |
4 |
|
0 |
|
H |
D |
2 |
2 |
8 |
|
1.000 |
|
I |
H |
6 |
8 |
16 |
|
2.778 |
|
J |
G, I |
4 |
6 |
14 |
|
2.778 |
|
K |
E, J |
2 |
2 |
5 |
|
0.250 |
a. Calculate the expected time for each activity. Enter these values in the appropriate column in the table above.
b. Which activities form the critical path?
c. What is the estimated time of the critical path?
d. What are the project variance and the project standard deviation?
e. What is the probability of completion of the project before week 40?
