Introduction to Management Science 12th Edition by Bernard Taylor

Exercise 11

The Stone River Textile Mill was inspected by OSHA and found to be in violation of a number of safety regulations. The OSHA inspectors ordered the mill to alter some existing machinery to make it safer (add safety guards, etc.); purchase some new machinery to replace older, dangerous machinery; and relocate some machinery to make safer passages and unobstructed entrances and exits. OSHA gave the mill only 35 weeks to make the changes; if the changes were not made by then, the mill would be fined $300,000. The mill determined the activities in a CPM/PERT network that would have to be completed and then estimated the indicated activity times, as shown in the following table:
Construct the project network for this project and determine the following:
a. Expected activity times
b. Earliest and latest activity times and activity slack
c. Critical path
d. Expected project duration and variance
e. The probability that the mill will be fined $300,000