Difference Between PERT and CPM (With Table)

Excellent project management skills play a pivotal role in the success of a business enterprise. These skills are crucial in the determination of the budget and time required for the achievement of a project’s goals. PERT and CPM are the two standard statistical techniques adopted to ensure time consciousness and cost-effectiveness in the completion of projects.

There are just two distinctions between them.

1) There is only a one-time estimation in CPM for each activity. In PERT there may be three-time estimations for a single activity.
2) CPM allows estimation of time and cost, hence controlling time and cost. PERT is a planning tool and only allows one to control time only.

What are the applications of PERT and CPM?

Applications of PERT and CPM and quite similar in approach.

There are a lot of applications of PERT and CPM mainly:

1) Construction projects like bridge, highway, dam
2) Design a new product and market it
3) Controlling production in large shops
4) R&D projects
5) Maintain equipment and hauling

What are the advantages and disadvantages of PERT and CPM?

There are many advantages and few disadvantages of PERT and CPM.
1) Helps you map all details in a diagram (easy to organize and measure the number of tasks and timelines)
2) A critical path would help you determine how an activity would affect the project deadline
3) A PERT diagram helps you think logically about resources and deadlines.
4) Helps you understand and measure the details that are required to be accomplished to not miss the deadline
5) Help you understand which paths can be delayed and which paths need more focus to not miss the deadline
6) Minimize the time and cost of the entire project.
7) Optimal utilization of resources


1) Works best when a person has the experience and understanding of the project otherwise the diagram is less useful.
2) It only works best when the team has the experience to estimate the accurate timeframe.
3) Diagram becomes complicated if the project is too big.
4) If the project is far too bulky and lengthy, all the map outlines become incomprehensible.
5) It cannot properly monitor the allocation of resources.
6) Inability to control the schedule of the person involved in the project.
7) Very difficult to redraw entire CPM if there are sudden changes in the implementation of the plan


The PERT technique is an event-based time estimation technique for projects whose activities are unpredictable and non-repetitive.

On the other hand, the CPM technique is an activity-based time and cost estimation technique for projects whose activities are predictable and repetitive.

Given the differences between the PERT and CPM techniques of project management, one can easily tell the optimal technique for whatever project is at hand.


  1. https://ascelibrary.org/doi/abs/10.1061/(ASCE)0733-9364(2000)126:3(219)
  2. https://books.google.co.in/books?hl=en&lr=&id=ODApoTanj4IC&oi=fnd&pg=PA1&dq=PERT+and+CPM&ots=y5xKkVNA5a&sig=ey7-Vc_m_riudGbO5nwm96vWDxw&redir_esc=y#v=onepage&q=PERT%20and%20CPM&f=false