MGT203 CH4

Chapter 4:

Objective Questions

5, 7, 8, 13

5.The following activities are part of a project to be scheduled using CPM:

a. Draw the network.

b. What is the critical path?
A-C-D-E-G, also shown in the network above as the bold path.
c. How many weeks will it take to complete the project?
6+7+2+4+7 = 26 weeks
d. How much slack does activity B have?
Activity B has 6 weeks of slack – the difference between its early and late start times.
7. The R&D department is planning to bid on a large project for the development of a new communications system for commercial planes. The accompanying table shows the activities, times, and sequences required:

a. Draw the network diagram.

Note that G has both D and F as immediate predecessors. However, D is redundant because F also has D as an immediate predecessor.
b. What is the critical path?
A-C-F-G-I, and A-D-F-G-I at 18 weeks.
c. Suppose you want to shorten the completion time as much as possible, and you have the option of shortening any or all of B, C, D, and G each one week. Which would you shorten?
B is not on a critical path and has slack of 4; therefore, do not shorten as it will not change the project completion time. Shorten C, D, and G one week each. C and D are on parallel critical paths, reducing them both will only reduce project completion time by 1 week.
d. What is the new critical path and earliest completion time?
A-C-F-G-I; and A-D-F-G-I remain the critical paths. Project completion time is reduced from 18 to 16 weeks.
8. The following represents a project that should be scheduled using CPM:

a. Draw the network.

TIMES (DAYS)

ACTIVITY
IMMEDIATE
PREDECESSORS a m b ET

A
—
1
3
5
3
0.4444
B
—
1
2
3
2
0.1111
C
A
1
2
3
2
0.1111
D
A
2
3
4
3
0.1111
E
B
3
4
11
5
1.7778
F
C, D
3
4
5
4
0.1111
G
D, E
1
4
6
3.833
0.6944
H
F, G
2
4
5
3.833
0.2500

b. What is the critical path?
B-E-G-H
c. What is the expected project completion time?
2.00+5.00+3.833+3.833 = 14.67
d. What is the probability of