PMI Scheduling Professional (PMI-SP) — Question 47

You are the project manager for the GRT Project in your organization. You have created your time duration estimates based on historical information, but the estimates are not holding true in your current project. Unfortunately, many activities are late. You have decided to create a PERT estimate with your project team for each of their activities. What is the formula used for PERT?

Answer options

• A. O+M+P
• B. (O+M+P)/3
• C. (O+4M+P)/6
• D. Average of the estimates

Correct answer: C

Explanation

The correct formula for PERT is (O+4M+P)/6, where O is the optimistic estimate, M is the most likely estimate, and P is the pessimistic estimate. This formula gives more weight to the most likely scenario, providing a more accurate estimate than simply averaging the three values or other methods. Options A, B, and D do not account for the weighted importance of the most likely estimate, making them less accurate for PERT analysis.