1. What is PERT and CPM?

PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method) are project management techniques used to plan, schedule, and control complex projects. PERT uses probabilistic time estimates while CPM uses deterministic time estimates.

2. How Does the Calculator Work?

The calculator uses the PERT formula:

Where:

• \( O \) — Optimistic time estimate (days)
• \( M \) — Most likely time estimate (days)
• \( P \) — Pessimistic time estimate (days)

Explanation: The PERT formula provides a weighted average that gives more importance to the most likely estimate while accounting for uncertainty through optimistic and pessimistic estimates.

3. Importance of PERT and CPM

Details: These techniques help project managers identify critical tasks, estimate project duration, allocate resources efficiently, and manage project risks effectively.

4. Using the Calculator

Tips: Enter optimistic, most likely, and pessimistic time estimates in days. All values must be non-negative numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between PERT and CPM?
A: PERT is probabilistic and handles uncertainty in time estimates, while CPM is deterministic and focuses on cost-time tradeoffs.

Q2: How is CPM duration calculated?
A: CPM duration is calculated by finding the longest path through the project network, which determines the minimum project completion time.

Q3: When should I use PERT vs CPM?
A: Use PERT for projects with high uncertainty in time estimates, and CPM for projects with well-defined activities and time estimates.

Q4: What are the limitations of PERT?
A: PERT assumes a beta distribution for time estimates and may not account for all dependencies and constraints in complex projects.

Q5: Can PERT and CPM be used together?
A: Yes, many project managers combine both techniques - using PERT for time estimation and CPM for critical path analysis.