The PERT method –acronym of Program Evaluation and Review Technique-, is a project management tool which allows managing coordination within a project. The output is a network model of tasks and links of a given project.

This network also called PERT chart allows to identify the critical path of a project and thus to focus the project’s efforts on critical tasks. The critical path is the chain of tasks which total duration is the project’s longest.

Invented in the end of the 1950s by the US Navy to coordinate tasks of POLARIS project (realization of nuclear warheads missiles), this method allowed to coordinate several thousand subcontractors, reducing costs and lead-time.

The PERT Chart or Diagram is often used as a complement of the Gantt Chart.

Numerous applications allow to model PERT networks. Like Microsoft Project, to quote only the most known of them, but there are also free “MS Project like” softwares like OpenProj à Free PERT Chart Tool

Components of a PERT Chart

In a PERT Chart or PERT Diagram, every task is associated with:

• A start date: date of the beginning of the task
• An end date: date of the end of the task
• A duration: generally in days, it is the difference between the start date and the end date of the task.
• Links: they are the links between the tasks determine the sequence of tasks The critical path often represented in red is easily identifiable thanks to the PERT diagram.

Example of PERT Chart