PMI-SP Time Estimating & Resource Allocation 3 — Questions and Answers
Question 1: An activity has an optimistic estimate of 3 days, a pessimistic estimate of 15 days, and a most likely estimate of 6 days. What is the PERT expected duration?
- 6 days
- 7 days (Correct answer)
- 8 days
- 9 days
Correct answer: 7 days
PERT = (3 + 4×6 + 15) / 6 = (3 + 24 + 15) / 6 = 42 / 6 = 7 days.
Question 2: What does a resource histogram primarily display?
- The sequence of activities assigned to each resource
- The amount of work planned for a resource over time (Correct answer)
- The cost of each resource per activity
- The float available for resource-constrained tasks
Correct answer: The amount of work planned for a resource over time
A resource histogram is a bar chart showing the quantity of resource usage over the project timeline, making over-allocations visually apparent.
Question 3: Which technique reassigns non-critical tasks to off-peak periods to smooth resource demand without changing the project end date?
- Resource leveling
- Resource smoothing (Correct answer)
- Fast-tracking
- Crashing
Correct answer: Resource smoothing
Resource smoothing adjusts activities within their available float to reduce peak resource demand while keeping the project finish date unchanged.
Question 4: A PMI-SP candidate needs to estimate effort for writing 50 test cases. Historical data shows a senior tester writes 5 test cases per day. What estimating technique uses this productivity rate?
- Three-point estimating
- Parametric estimating (Correct answer)
- Analogous estimating
- Bottom-up estimating
Correct answer: Parametric estimating
Parametric estimating multiplies a unit productivity rate (5 test cases/day) by the quantity (50 test cases) to derive the effort estimate.
Question 5: When a project has a fixed end date and insufficient resources, which strategy is MOST appropriate?
- Extend activity durations to reduce resource requirements
- Add resources to critical path activities (Correct answer)
- Remove non-critical activities from the schedule
- Apply resource smoothing to all tasks
Correct answer: Add resources to critical path activities
Adding resources to critical path activities (crashing) can compress the schedule to meet a fixed end date when resources are the constraint.
Question 6: The standard deviation of a PERT activity estimate is calculated as:
- (P - O) / 6 (Correct answer)
- (P + O) / 2
- (P - O) / 3
- (P - M) / 6
Correct answer: (P - O) / 6
The standard deviation for a PERT estimate is (Pessimistic - Optimistic) / 6, representing the uncertainty spread of the estimate.
Question 7: What term describes the maximum amount of time an activity can be delayed from its early start without delaying any successor activity?
- Total float
- Free float (Correct answer)
- Project float
- Negative float
Correct answer: Free float
Free float is the amount of time an activity can be delayed without affecting the early start of any immediately following activity.
PMI-SP Time Estimating & Resource Allocation 3
An activity has an optimistic estimate of 3 days, a pessimistic estimate of 15 days, and a most likely estimate of 6 days.
What is the PERT expected duration?