Difference Between PERT and CPM

Project Evaluation and Review Technique (PERT) and Critical Path Method (CPM) are very important analytical techniques of Project Management for planning and controlling a project. PERT and CRM are helpful tools for managing tasks that every project manager should implement.

Understanding the differences between PERT and CPM is essential for utilizing their combined strengths to effectively manage project tasks and timelines. Before understanding differences, let’s first understand their definition.

PERT stands for Project Evaluation and Review Technique. This is an appropriate technique that is used for projects where the time required or needed to complete different activities is not known. This planning tool is used to calculate the amount of time it will take to realistically finish a project. It provides the blueprint of project and is an efficient technique for project evaluation.

In this technique, a PERT Chart is made which represents a schedule for all the specified tasks in the project. The PERT chart is used to schedule, organize, and coordinate tasks within the project. The objective of the PERT chart is to determine the critical path, which comprises critical activities that should be completed on schedule.

CPM is a technique that is used for projects where the time needed for completion is already known. It is primarily used for determining the approximate time within which a project can be completed. The critical path is the largest path in project management that always results in the shortest time to complete the project.

CPM also helps project managers identify critical tasks and non-critical tasks, allowing them to prioritize resources and manage project schedules effectively.

Aspect	PERT	CPM
Abbreviation	PERT stands for Project Evaluation and Review Technique.	CPM stands for Critical Path Method
Definition	PERT is a technique of project management which is used to manage uncertain (i.e., time is not known) activities of any project.	CPM is a technique of project management which is used to manage only certain (i.e., time is known) activities of any project.
Orientation	It is event oriented technique which means that network is constructed on the basis of event.	It is activity oriented technique which means that network is constructed on the basis of activities.
Model Type	It is a probability model.	It is a deterministic model.
Focus	It majorly focuses on time as meeting time target or estimation of percent completion is more important.	It majorly focuses on Time-cost trade off as minimizing cost is more important.
Precision	It is appropriate for high precision time estimation.	It is appropriate for reasonable time estimation.
Nature of Job	It has Non-repetitive nature of job.	It has repetitive nature of job.
Crashing	There is no chance of crashing as there is no certainty of time.	There may be crashing because of certain time bound.
Dummy Activities	It doesn’t use any dummy activities.	It uses dummy activities for representing sequence of activities.
Sustainability	It is suitable for projects which required research and development.	It is suitable for construction projects.

CPM Example

Effective Task Scheduling: PERT is ideal for scheduling tasks in projects and determining the critical path, which is essential for understanding project timelines.
Timely Decision Making: Both PERT and CPM enable project managers to make timely decisions during project execution, helping to prevent delays and ensure on-time project delivery. PERT is particularly useful for exploring different scenarios, while the critical path identified by CPM helps identify potential uncertainties.
Promoting Department Coordination: Using both techniques promotes coordination among project departments and facilitates decision-making for cross-functional teams by providing ample data. This analysis aids in managing the project within budget constraints.
Long-Term Planning and Milestone Identification: CPM assists in long-term planning by identifying critical tasks, streamlining planning, scheduling, and project control, resulting in increased productivity and better resource management. PERT, on the other hand, identifies project milestones and task sequences visually, aiding in team comprehension. Regular updates to PERT charts throughout the project lifecycle ensure continued benefits.

Both PERT and CPM are valuable project management tools, each with its own advantages. PERT helps in scheduling tasks and exploring different scenarios, while CPM assists in long-term planning by identifying critical tasks. Together, they enable timely decision-making, promote department coordination, and ensure projects stay on track. PERT is visual and aids in milestone identification, while CPM focuses on outlining the critical path for efficient project management. Combining both techniques provides a comprehensive approach to project planning, scheduling, and control, leading to successful project delivery.

1. What is the difference between CPM and PERT?

PERT is a technique of project management used to manage uncertain activities of a project where time is not known. while CPM is a technique of project management used to manage certain activities of a project where time is known.

2. What is the full form of PERT?

PERT stands for Program Evaluation Review Technique.

3. Why is PERT used?

PERT is used to calculate the total amount of time to finish a project.

4. Who uses PERT?

PERT chart is used by Product Manager.

What is PERT?

What is CPM?