PMP Practice Questions #113
You are leading a project to upgrade the IT infrastructure of a large corporation. For the task of migrating data to the new system, your team has provided the following estimates:
Optimistic time (O): 12 days
Most likely time (M): 18 days
Pessimistic time (P): 30 days
Using the three-point estimation with a triangular distribution, what is the expected time (TE) for the data migration task?
A) 18 days
B) 19 days
C) 17 days
D) 20 days
Analysis:
When managing a project to upgrade IT infrastructure, specifically for the task of migrating data to a new system, it’s critical to accurately estimate the task duration to ensure project timelines are met. The team has provided optimistic, most likely, and pessimistic estimates for this task. To derive an expected time (TE) for the data migration task using a three-point estimation with a triangular distribution, a straightforward calculation is employed that equally weights the optimistic, most likely, and pessimistic times. This approach differs from the PERT technique, which applies a weighted average, giving more significance to the most likely time.
Standard Calculation for Expected Time (TE) with Triangular Distribution:
The formula for calculating the expected time using a triangular distribution is a simple average of the three estimates: TE=(O+M+P)/3
Given the estimates:
- Optimistic time (O): 12 days
- Most likely time (M): 18 days
- Pessimistic time (P): 30 days
Calculation:
TE=(12+18+30) / 3=60/3=20 days
Analysis of Options:
Option A: 18 days – This option incorrectly suggests the most likely estimate as the expected time, overlooking the triangular distribution method.
Option B: 19 days – This does not match the expected time derived from the triangular distribution calculation.
Option C: 17 days – Also incorrect, as it does not align with the calculated average of the three estimates.
Option D: 20 days – This is the correct answer, directly resulting from the calculation using the triangular distribution formula, equally considering all three-time estimates.
Conclusion: Option D) 20 days is the correct expected time for the data migration task, calculated using the three-point estimation with a triangular distribution. This method offers a balanced approach to estimating task duration by averaging the optimistic, most likely, and pessimistic times, providing a realistic timeframe for project scheduling and management.
PMP Exam Content Outline Mapping
| Domain | Task |
|---|---|
| Process | Task 6: Plan and manage schedule |
Topics Covered
- Three Point Estimation
- Triangular Distribution
