PMI-SP Duration Estimating 2 — Questions and Answers
Question 1: A project manager is estimating durations for a software integration task. The most optimistic estimate is 4 days, the most likely is 9 days, and the most pessimistic is 20 days. What is the PERT expected duration?
- 9.0 days
- 10.0 days (Correct answer)
- 10.5 days
- 11.0 days
Correct answer: 10.0 days
PERT expected duration = (O + 4M + P) / 6 = (4 + 36 + 20) / 6 = 60 / 6 = 10.0 days.
Question 2: Which duration estimating technique is MOST appropriate when a project team has little historical data but access to subject matter experts?
- Parametric estimating
- Bottom-up estimating
- Expert judgment (Correct answer)
- Analogous estimating
Correct answer: Expert judgment
Expert judgment is most appropriate when historical data is scarce but knowledgeable SMEs are available to provide informed estimates.
Question 3: A schedule estimator is using the reserve analysis technique. Which type of reserve is added to activity durations to account for identified risks?
- Management reserve
- Contingency reserve (Correct answer)
- Budget reserve
- Planning reserve
Correct answer: Contingency reserve
Contingency reserve is added to activity durations to address identified schedule risks, unlike management reserve which covers unknown unknowns.
Question 4: When using parametric estimating, a construction team knows it takes 2 hours per linear foot for a specific type of piping installation. If the project requires 150 linear feet, what is the estimated duration?
- 75 hours
- 150 hours
- 300 hours (Correct answer)
- 225 hours
Correct answer: 300 hours
Parametric estimate = rate × quantity = 2 hours/foot × 150 feet = 300 hours.
Question 5: A project manager notices that duration estimates provided by team members consistently underestimate actual time. Which bias is MOST likely causing this?
- Halo effect
- Student syndrome
- Optimism bias (Correct answer)
- Anchoring bias
Correct answer: Optimism bias
Optimism bias causes estimators to consistently underestimate durations by assuming best-case conditions will prevail.
Question 6: In the three-point estimating approach, what does a high standard deviation in activity duration estimates indicate?
- The estimate is highly accurate
- There is high uncertainty in the estimate (Correct answer)
- The activity has low priority
- Expert judgment was not used
Correct answer: There is high uncertainty in the estimate
A high standard deviation indicates a wide spread between optimistic and pessimistic estimates, reflecting high uncertainty.
Question 7: Which input is MOST critical when using analogous estimating for duration estimation?
- Resource calendars for the current project
- Historical information from similar past projects (Correct answer)
- The current project's work breakdown structure
- Monte Carlo simulation results
Correct answer: Historical information from similar past projects
Analogous estimating relies on historical information from similar completed projects as its primary basis for duration estimates.
PMI-SP Duration Estimating 2
A project manager is estimating durations for a software integration task.
The most optimistic estimate is 4 days, the most likely is 9 days, and the most pessimistic is 20 days.
What is the PERT expected duration?