PERT/CPM Problem

The Nevada-based Debug Software Company (SC) develops software for the entertainment industry. One of their software development projects involves 20 separate activities. The table below provides optimistic, most likely, and pessimistic time estimates in weeks for this project. Please answer the following questions. Identify your answer to each question clearly. Show calculations and comment on results. You may be asked to describe how you arrived at your answers. (All the calculations should be rounded up to two decimals if necessary)

1. Construct a network for this project; networks with crossed paths are not acceptable.

2. Determine the expected time and variance for each activity (shown in a table).

3. Determine the ES, EF, LS, LF, and slack for each activity (show it either in a table or in the PERT diagram).

4. Determine the critical path and project completion time.

5. What is the probability that the project will be finished in 44 weeks?

6. What is the probability that the project will be finished in 51 weeks?

7. Assuming that activity J took exactly 10 weeks to complete (all else remains the same), what is the impact on the expected project completion time? What is the impact on the critical path? Explain.

8. Assuming that activity M took exactly 36 weeks (all else remains the same), how many weeks are needed to finish the project with 98% probability for sure? Show new network.

9. What would happen to the critical path and project completion time if activity F has optimistic, most likely, and pessimistic time estimates of 7, 8, and 9 weeks respectively? Explain your answer.