American Institute of Certified Planners (AICP) Practice Exam

What is the primary distinction between PERT and CPM in project management?

1. PERT involves fixed task times.

2. CPM allows for variable task times.

3. PERT utilizes variable task times.

4. CPM is based on a flexible schedule.

The correct answer is: PERT utilizes variable task times.

The primary distinction between PERT (Program Evaluation Review Technique) and CPM (Critical Path Method) lies in their approach to time estimation for project tasks. PERT is particularly designed for projects where the time required to complete each task is uncertain or variable. It employs a probabilistic approach by utilizing three different time estimates for each task: optimistic, pessimistic, and most likely. This allows project managers to account for uncertainty in scheduling and to create a more flexible project timeline. On the other hand, CPM is used for projects where task durations are predictable and fixed. It relies on a deterministic approach, meaning each task is assigned a single fixed duration. This results in a clear understanding of the critical path, or the longest sequence of tasks that determines the project's shortest possible duration. Thus, the correct choice reflects that PERT effectively accommodates variable task times, making it suitable for managing projects with uncertain durations. This distinction is crucial for project managers when selecting the appropriate method based on the nature of the tasks involved in their projects.