Sample Problem: PERT Expected Time Calculation
Example
Problem Statement: An activity has the following time estimates: Optimistic () = 4 days, Most Likely () = 7 days, and Pessimistic () = 16 days. Calculate the expected duration () and the variance () of the activity.
Step-by-Step Solution
0 of 3 Steps Completed1
Sample Problem: PERT Probability of Completion
Example
Problem Statement: A project has an expected critical path length () of 40 days and a project standard deviation () of 2 days. What is the probability that the project will be completed in 43 days or less?
Step-by-Step Solution
0 of 4 Steps Completed1
Sample Problem: Critical Path and Total Float
Example
Problem Statement: Activity D has an Early Start (ES) of day 10, a duration (t) of 5 days, a Late Finish (LF) of day 20. Calculate the Early Finish (EF), Late Start (LS), Total Float (TF), and Free Float (FF) if its only successor, Activity E, has an ES of day 17.
Step-by-Step Solution
0 of 5 Steps Completed1
Sample Problem: Schedule Crashing (Cost Slope)
Example
Problem Statement: An activity normally takes 10 days and costs $5,000. It can be "crashed" (expedited) to 7 days at a total cost of $6,500. Calculate the cost slope. If the project manager needs to save 2 days on the critical path, how much extra will it cost?
Step-by-Step Solution
0 of 4 Steps Completed1
Key Takeaways
- PERT Uncertainty: The PERT expected time () provides a statistically weighted duration that heavily emphasizes the 'most likely' scenario while accounting for optimistic and pessimistic extremes.
- Float Differentiation: Total Float affects the whole project deadline, whereas Free Float only affects the immediate successor's start date.
- Schedule Crashing: Always crash activities on the Critical Path that have the lowest cost slope first to minimize the financial impact of acceleration.