The PERT method is a technique that allows you to manage the scheduling of a project. The PERT method consists of graphically representing a network of tasks, which, when placed in a chain, can lead to the achievement of the objectives of a project.
It was designed by the US navy to allow for coordination of the work of several thousand persons to build missiles with POLARIS nuclear warheads.
The PERT method includes the following at the preliminary stage:
- Precise breakdown of the project into tasks;
- Estimation of the duration of each task;
- The appointment of a project manager in charge of assuring monitoring of the project, reporting, if necessary, and making decisions in the event of deviations from projections.
The PERT network (sometimes called PERT graph) consists of the following elements:
- Task (sometimes activity or stage), represented by an arrow. A code and a duration are assigned to each task. However, the length of the arrow is independent of the duration.
- Stage, i.e. the beginning and end of a task. Each task has a start and end stage. With the exception of the initial and final stages, each end stage is the beginning stage of the next task.The stages are generally numbered and represented by a circle, but they may sometimes be represented by other shapes (square, rectangle, oval, etc.).
- Fictitious task, represented by a dotted arrow, indicates the limitations on task chains between certain stages.