A PERT chart gives a visual representation of the critical path of a project. This critical path is the sequence of interdependent activities that will require the longest time period to complete. Each task on the chart is labeled with high and low estimated start and finish times, which can be used to determine where there is slack in the system and where to focus attention on compressing the schedule. In addition, the chart contains all tasks that must be addressed before a project can be completed, the sequence in which they must be completed, and the time requirements for each one. A PERT chart is especially useful for the management of more complex projects that would overwhelm a Gantt chart.
The PERT acronym is an abbreviation of the term Program Evaluation and Review Technique.