Difference between PERT and CPM
Introduction
PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method) are two popular project management techniques that can help businesses to schedule and complete their projects efficiently. However, many people are confused about the difference between these two methods. In this article, we will compare PERT and CPM to help you choose the best fit for your business.
What is PERT?
PERT is a project management technique that is used to analyze and represent the tasks involved in completing a project. PERT is used to estimate the time required to complete each task and identify the dependencies between them. PERT is commonly used in the construction, engineering, and development sectors.
What is CPM?
CPM is also a project management technique that is used to schedule and complete projects. CPM is primarily used in manufacturing and construction industries to determine the shortest time to complete a project. CPM helps to identify the critical path, which is the sequence of tasks that must be completed on time to keep the project on schedule.
The main difference between PERT and CPM
The main difference between PERT and CPM is that PERT is probabilistic, while CPM is deterministic. PERT considers that there is a range of possible durations for each activity, and it uses three different time estimates to estimate the duration of each activity. Meanwhile, CPM considers that there is only one definite duration for each activity and calculates the expected duration of each task based on historical data.
When to use PERT or CPM?
PERT is best suited for projects that are complex, have a high degree of uncertainty or subjectivity, require the use of subjective assessment techniques like expert judgment, and have many parallel or concurrent activities. PERT is also useful when there is a need to reduce the level of risk or uncertainty involved in a project.
CPM is best suited for projects that are less complex or have low levels of uncertainty, where the duration of each activity can be accurately determined, and where historical data is available. CPM is also useful for projects with a strict deadline or have limited resources.
Conclusion
Both PERT and CPM are effective project management techniques that can help businesses to complete their projects efficiently. However, the choice between PERT and CPM depends on the nature of the project, its level of complexity, and the amount of uncertainty involved. It is important to carefully evaluate your project requirements to select the best fit.
Table difference between pert and cpm
| Pert | CPM |
|---|---|
| Program Evaluation and Review Technique | Critical Path Method |
| Used for uncertain activities with multiple possible outcomes | Used for activities with a known duration |
| Accounts for probabilistic estimates | Accounts for deterministic estimates |
| Focuses on the longest path | Focuses on the critical path |
| Uses three time estimates for each activity (optimistic, most likely, pessimistic) | Uses a single duration estimate for each activity |
| Used when there is high uncertainty in project timelines | Used when there is low uncertainty in project timelines |
| Accounts for slack time in schedule | Assumes no slack time and a linear relationship between activities |