Project Evaluation and Review Technique (PERT) (original) (raw)
Last Updated : 21 Aug, 2025
**Project Evaluation and Review Technique (PERT) is a procedure through which activities of a project are represented in its appropriate sequence and timing. It is a scheduling technique used to schedule, organize and integrate tasks within a project. PERT is basically a mechanism for management planning and control which provides blueprint for a particular project. All of the primary elements or events of a project have been finally identified by the PERT.
In this technique, a PERT Chart is made which represent a schedule for all the specified tasks in the project. The reporting levels of the tasks or events in the PERT Charts is some what same as defined in the work breakdown structure (WBS).
PERT chart
What is PERT Chart?
A PERT chart is a project management tool used to plan and schedule tasks, illustrating the sequence and timing of project activities. The PERT chart is used to schedule, organize and co-ordinate tasks within the project. the objective of PERT chart is to determine the critical path, which comprises critical activities that should be completed on schedule. This chart is prepared with the help of information generated in project planning activities such as estimation of effort, selection of suitable process model for software development and decomposition of tasks into subtasks.
What does a PERT Chart Contain?
Here are the main components of a PERT chart:
- **Nodes: it represents the task or milestones. every node represents the task name and may also show duration of the task.
- **Arrows: it indicates the direction or sequence of task and also dependencies between them. suppose an array from A to B, then task A must be completed before task B.
- **Time Estimation: It estimates the time duration to complete the task.
- **Critical Path: The critical path is the largest path in project management that always results in the shortest time to complete the project.
- **Milestones: It is Key point in the project timeline that represent significant events or deadlines.
How a PERT Chart Works?
A **PERT chart used to plan and visualize tasks in a project. It breaks down the project into individual tasks and shows the sequence in which they must be completed. Each task is represented by a node, and arrows indicate the dependencies between tasks. By analyzing the chart, teams can identify the critical path, which helps determine the shortest time to complete the project and allocate resources effectively.
How to Create a PERT chart?
To create a PERT chart, we can follow the below steps:
Step 1: Identify Project Tasks
List all the tasks required to complete the project. Identifying tasks means listing all the steps needed to complete a project. Start by figuring out what the main goal is, then break it down into smaller actions. Ask team members for ideas and use clear action words for each task.
Step 2: Define task dependencies
Defining task dependencies means figuring out which tasks must be completed before others can start. Look at your task list and identify connections by asking if one task relies on another. This helps you establish the order of work, ensuring everything is done in the right sequence.
Step 3: Estimate Timeline
Estimating the timeline involves figuring out how long each task will take to complete. For each task, think about the quickest time it could be done (optimistic), the longest it might take (pessimistic), and the most likely time it will actually take. This gives you a better idea of the overall project duration and helps with planning.
Step 4: **Calculate Critical Path
Calculate Critical Path means finding the longest sequence of tasks that determines the shortest time to complete the project. Identify which tasks can’t be delayed without affecting the overall project deadline, helping you focus on what’s most important.
Step 5: Manage task progress
It involves tracking how each task is going. Regularly check if tasks are on schedule, address any delays, and adjust plans if needed. This ensures the project stays on track and any issues are resolved quickly.
PERT Chart Vs Gantt Chart
Here is a comparison of PERT and Gantt charts in a detailed way:
| Feature | PERT Chart | Gantt Chart |
|---|---|---|
| Purpose | Visualize project tasks and dependencies | Schedule tasks over time |
| Focus | Task relationships and sequence | Task duration and timeline |
| Representation | Network diagram with nodes and arrows | Horizontal bar chart |
| Time Estimation | Includes optimistic, pessimistic, and most likely durations | Shows start and end dates |
| Complexity | More complex, suitable for large projects | Simpler, easier to read |
| Flexibility | Adaptable for changing project paths | Less flexible once established |
| Best Use Case | Research and development projects | Construction and production schedules |
What is PERT vs CPM?
Here are the following difference between PERT and CPM:
| 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. |
**Characteristics of PERT Chart
The main characteristics of PERT are as following:
- It serves as a base for obtaining the important facts for implementing the decision-making.
- It forms the basis for all the planning activities.
- PERT helps management in deciding the best possible resource utilization method.
- PERT take advantage by using time network analysis technique.
- PERT presents the structure for reporting information.
- It helps the management in identifying the essential elements for the completion of the project within time.
- It specifies the activities that from the critical path.
- It describes the probability of completion of project before the specified date.
- It describes the dependencies of one or more tasks on each other.
- It represents the project in graphical plan form.
**Advantages of PERT Chart
It has the following advantages:
- Estimation of completion time of project is given by the PERT.
- It supports the identification of the activities with slack time.
- The start and dates of the activities of a specific project is determined.
- It helps project manager in identifying the critical path activities.
- PERT makes well organized diagram for the representation of large amount of data.
**Disadvantages of PERT Chart
It has the following disadvantages:
- The complexity of PERT is more which leads to the problem in implementation.
- The estimation of activity time are subjective in PERT which is a major disadvantage.
- Maintenance of PERT is also expensive and complex.
- The actual distribution of may be different from the PERT beta distribution which causes wrong assumptions.
- It under estimates the expected project completion time as there is chances that other paths can become the critical path if their related activities are deferred.
Conclusion
In conclusion, the **Project Evaluation and Review Technique (PERT) is a valuable tool for effective project management. It helps teams visualize the sequence of tasks, understand dependencies, and identify the critical path for timely project completion. By using PERT, organizations can improve planning, resource allocation, and overall project success, ensuring that goals are met efficiently and effectively.