Final answer:
PERT and CPM are both project management tools, but PERT considers the uncertainty in task durations while CPM assumes fixed durations. PERT uses three time estimates for each task, while CPM focuses on identifying the critical path.
Step-by-step explanation:
PERT, or Program Evaluation and Review Technique, is a project management tool that is used to analyze and schedule the tasks involved in completing a project. It is a probabilistic method that takes into account the uncertainty associated with the time required for each task.
CPM, or Critical Path Method, is also a project management tool that is used to identify the critical activities and determine the shortest possible time to complete a project. It is a deterministic method that assumes fixed durations for each task.
The main difference between PERT and CPM is that PERT considers the uncertainty and variability in task durations, while CPM assumes fixed durations for tasks. PERT uses three time estimates for each task - optimistic, pessimistic, and most likely - to calculate the expected duration and variance of the project. CPM focuses on identifying the critical path, which is the longest sequence of dependent tasks that determines the project's duration.