The following table shows the probabilistic activity time estimates for the CPM/PERT network in Problem 9-9.

Determine the following:
a. Expected activity times
b. Earliest start and finish times
c. Latest start and finish times
d. Activity slack
e. Critical path
f. Expected project duration and standard deviation

Problem 9-9

In one of the little-known battles of the U.S. Civil War, General Tecumseh Beauregard lost the Third Battle of Bull Run because his preparations were not complete when the enemy attacked. If the critical path method had been avail-able, the general could have planned better. Suppose that the following project network with activity times in days had been available. 

Time Estimates (days) Activity a m 1 1 3 5 10 4 6. 14 4 9. 6. 3 7 1 1.5 1 1 1 10 2 4 11 12 2. 3. 2. 2. 3. Move Build Create engineering division pontoon bridges supply lines 2 5 11 2 2 Advance cavalry Develop plan Artillery Cavalry reconnaissance placement scout Attack 1 3 12 2 Plan fortifications 3 10 3 Cavalry disruption of enemy supply lines 4 3 Army march Troops build earthworks