18 A plant engineering group needs to set up an assembly line to produce a new product. The table in the next column describes the relationships between the activities that need to be completed for this product to be manufactured.

(a) Develop a project network for this problem.

(b) Determine the expected duration and variance for each activity.

(c) Determine the EST, EFT, LST, LFT, and slack for each activity. Also determine the total project completion time and the critical path(s).

(d) Determine the probability that the project will be completed in less than 34 days.

(e) Determine the probability that the project will take more than 29 days.

ACTIVITY DAYS IMMEDIATE a m b PREDECESSORS A 3 6 6 —

B 5 8 11 A C 5 6 10 A D 1 2 6 B, C E 7 11 15 D F 7 9 14 D G 6 8 10 D H 3 4 8 F, G I 3 5 7 E, F, H