3. Consider the PERT time estimates:

Activity Immediate

Predecessors a m b

A 2 5 9

B A 1 6 8

C A 3 5 12

D B 2 4 12

E B, C 4 6 8

F B 6 7 8

G D, E 1 2 6

H F, G 4 6 16

Draw a network for this project and determine the critical path based on the most likely times by inspection.

1. Which of the following is the critical path?

1. A-C-E-G-H
2. A-B-F-H
3. A-B-E-G-H
4. A-B-G-H

2. What is the expected path length?
3. What is the variance of the path length?
4. What is the probability that the project will be completed before 28 weeks (in decimal value)?
5. What is the probability that the project will be completed before 32 weeks (in decimal value)?
6. Assuming the critical path identified using the most likely times, how many days are required to complete the project with probability of 95%?