Unit 2 Exercise

1. Below is a network diagram that represents a university revamp project. The project manager analyzes this project using the critical path (CP) method. Activity durations are indicated on the network.

(a) Which is the CP?

(b) Calculate the duration of the CP.

(c) Calculate the amount of slack time at activity H.

(d) If activity I were delayed by ten time-units, what would be the impact on the project duration?

2. Consider the network described in the table below.

Activity

Immediate

Predecessor(s)

Pessimistic

Probable

Optimistic

J

--

15

10

8

K

--

9

8

7

L

J

10

6

5

M

J

3

3

3

N

K, M

9

5

1

O

K, M

10

7

4

P

L, N

10

8

3

Draw the network diagram and answer the following questions.

(a) Calculate the expected duration of each activity.

(b) Calculate the expected duration and variance of the critical path.

(c) Calculate the probability that the project will be completed in more than 28 weeks time units.

3. The client of a project has requested the project team to crash 8 hours of time. The table below provides the necessary information about the possible project crashing.

(a) What is the crash cost for 8 hours of time-savings?

(b) Assume the team calls the client and asks for a project extension, reducing the amount of time they need to crash. The project team has a $20 crash budget. Is the budget sufficient to crash 4 hours of time?

Activity

Normal

Duration (hours)

Normal

Cost ($)

Crash

Duration (hours)

Crash

Cost (S)

Immediate

Predecessors

A

2

10

2

0

None

B

3

15

2

23

A

C

5

25

4

30

B

D

3

20

1

24

C

E

6

30

4

45

C

F

1

5

1

0

C,E

G

7

35

6

50

F

H

10

50

7

62

D,G