PERT (Program Evaluation and Review Technique) is a project management tool used to plan and schedule tasks in a project, particularly when the duration of tasks is uncertain. It is widely used in operations research to manage complex projects with unpredictable timelines.

PERT was developed in 1958 by the U.S. Navy and Lockheed for the Polaris submarine missile program.

Key Concepts:

1. Time Estimates: PERT uses three time estimates for each task:

   • Optimistic time (O): The best-case scenario.
   • Pessimistic time (P): The worst-case scenario.
   • Most likely time (M): The expected time under normal conditions.
   • The expected time (TE) for each task is calculated using the formula: TE = (O + 4M + P)/6
     

2. Network Diagram: A visual representation of the project showing tasks as nodes and dependencies as arrows.

3. Critical Path: The longest sequence of dependent tasks that determines the project’s minimum completion time. Any delay in tasks on the critical path delays the entire project.

4. Slack Time: The amount of time a task can be delayed without affecting the overall project completion time. Tasks not on the critical path typically have slack

Benefits:

• Helps manage uncertainty in task durations.
• Focuses on time estimation and project scheduling.
• Helps identify the critical tasks that must be completed on time to avoid project delays.

Limitations:

• Can be complex for large projects.
• Relies on accurate time estimates, which can be difficult to predict.
• Primarily focuses on time, without directly addressing cost or resource allocation.

In short, PERT is a useful technique for managing projects with uncertain timelines by providing a framework for estimating task durations, planning the schedule, and identifying the critical path to ensure timely project completion.