PMI CAPM (Certified Associate in Project Management) Examination Content OutlinePredictive, Plan-Based MethodologiesMedium
A project manager is developing a schedule for a complex engineering project. The team has identified all activities and their dependencies. Now, the project manager needs to estimate the duration of each activity. For a particular activity, the optimistic estimate is 8 days, the pessimistic estimate is 20 days, and the most likely estimate is 11 days. Using the Three-Point (Beta) distribution, what is the expected duration for this activity?
- A12.0 days
- B11.5 days
- C12.5 days
- D13.0 days
Show answer & explanationAnswer & explanation
Correct answer: A. 12.0 days
The Three-Point (Beta) distribution formula for expected duration (Te) is (Optimistic + 4 * Most Likely + Pessimistic) / 6. Plugging in the values: (8 + 4 * 11 + 20) / 6 = (8 + 44 + 20) / 6 = 72 / 6 = 12 days.
Why the other options are wrong
- B. Incorrect calculation using the Beta distribution formula.
- C. Incorrect calculation, possibly using a triangular distribution or miscalculation.
- D. Incorrect calculation, possibly miscalculation.
Three-Point (Beta) Estimate
A technique used to estimate activity duration or cost by taking a weighted average of optimistic, pessimistic, and most likely estimates.
- Formula: (Optimistic + 4 * Most Likely + Pessimistic) / 6.
- Provides a more realistic estimate by accounting for uncertainty.
- Particularly useful for activities with high uncertainty.
Memory trick: Estimate durations, but remember the 'OPM' formula for accuracy.