What Are CPM And PERT | Difference Between The CPM And PERT | Advantages Of CPM And PERT Network

The CPM and PERT are very powerful numerical tools of project management and facilitate the work of planning, organizing, scheduling, controlling, monitoring, and evaluating the project in the most effective way.

Critical Path Method (CPM)

The CPM in civil engineering stands for the Critical Path Method which is a numerical tool used to find an effective way for the project management and planning of construction work.

In the critical path method (CPM), the time for the construction of any project is already known and this time is an approx time.

The critical path is the longest path of activity to complete the entire construction of work in the minimum time.

Project/Programme Evaluation And Review Technique(PERT)

The PERT in civil engineering stands for the Project/Programme Evaluation And Review Technique.

The PERT is a numerical technique that is used to find an effective way for project management and planning of construction work.

The project evaluation and review technique is suitable for the research-based construction project where the time is not known.

The PERT system involves a probabilistic approach and the nature of the PERT work is non-repetitive.

The PERT introduce three kinds of time estimates of the activity duration which are below-

1. Optimistic Time Estimate (t_o)
2. Pessimistic Time Estimate (t_p)
3. Most Likely Time Estimate (t_m)

Advantages Of CPM And PERT Network

CPM and PERT network has many advantages in the construction management in the various phases of civil engineering project-

1-Planning Phase: In the planning phase the CPM and PERT network Plays an important role to find out the alternative works and helps in choosing the best plan based on minimum time and minimum cost.

2-Organizing Phase: The CPM and PERT help in awarding the contract to the best and efficient contractor because the network created by the contractor with tender is a mirror image of resource capacity.

3-Scheduling Phase: Scheduling is the determination of the timing of the operation of the projects in the various calendars:

1. From Starting date to finishing date, the delivery time of materials is clearly mentioned on material calender.
2. Type, quantity and duration of equipments needs are mentioned on equipment calender with date.
3. The requirment of Labours number, types of labours are mention on the labour calender,
4. The time upto which the financial aid needed for payment of materials, equipments and labours are must written on finance calender.
5. In the activity time calender the sarting and finishing date for each activity to complete the project must be mentioned.

4-Controlling And Monitoring Phase: The CPM and PERT network helps in controlling and monitoring the execution of the project activities to ensure that the construction work is completed on the given time.

5- Evaluating Phase: After the completion of the construction project, the evaluation phase comes in the role, and in this, we have to evaluate the deviation in the actual time, actual coat and the panned time, planned coat of the project.

The reasons for the deviation in the project should be analyzed and a report is made available to the executive for use in the future project.

Difference Between CPM And PERT

CPM	PERT
The CPM stands for the Critical Path Method.	The PERT stands for the Project/Programme Evaluation And Review Technique.
The CPM is a deterministic approach in the design of a network.	PERT is a probabilistic approach in the design of network
In the CPM the time of completion of the project is known.	In the PERT the time of completion of the project is not known.
In the CPM only one estimate is required for each activity	In the PERT three estimate (Optimistic time, pessimistic time, Most likely time) is required for each activity
CPM is built-up of the activity-oriented diagram	PERT is built-up of the event-oriented diagram.
In CPM critical events must have zero slack.	In the PERT the critical events may be positive, negative, or zero slack.
The CPM is a repetitive nature of work.	The PERT is non-repetitive nature of work.
The CPM does use dummy activity.	The PERT does not use dummy activity.
The CPM is good for construction projects.	The PERT is good for research-based projects.

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