• PERT is a well-known graphical technique for portraying such a time-phased plan and displaying the appropriate milestones.
• PERT stands for Program Evaluation and Review Technique.
• The PERT system has the advantage of showing the order in which events must be completed.
• It also shows that some events must be done before others and illustrates where bottlenecks are likely to occur.

Important point for PERT chart

• A PERT chart (network diagram) is a tool that facilitates decision-making and is an event and activity illustration of connectivity between activities.
• Two consecutive events in a PERT chart are linked by activities, which are conventionally represented as arrows.
  The length of the arrow has nothing to do with time
• The events are presented in a logical sequence and no activity can commence until its immediately preceding event is completed.
• The project planner decides which milestones should be PERT events and also decides their "proper" sequence.