Use the three-point estimates to determine the duration for each activity. Create a table to determine activity
durations using three different distributions:
• The PERT (Beta) distribution (pessimistic + 4*most likely+optimistic)/6
• The Triangular distribution (pessimistic + most likely + optimistic)/3
• The Uniform distribution (optimistic + pessimistic)/2
Examining the impact of applying different distributions. The critical path is already identified—just use the
three-point estimates provided in columns D,E, and F, and calculate the critical path duration in columns K & L.
Do this three times using the different distributions and evaluate how the outcome changes. Column L is you
will input the PERT calculations. All of this is done prior to adding resources—it is an estimate. Only the critical
path activities are used in PERT.
As to the network diagram. Create the network diagram in Excel for the critical path shown. It
is just a way to show that the critical path has zero float (slack). “
Sample Solution
