The critical path is one way to evaluate a schedule. It is defined by the activities which will determine the shortest expected completion of the project. If any of the activities on the critical path takes longer, the project will take longer. The calculation is based on the expected activity durations and the dependencies between them.
The critical path can be changed by adjustments to the resources that are available or other changes to the schedule. Some of the types of schedule changes would include adjustments to the dependencies or timing of events like approval gates.
Some advantages of determining the critical path are
- gaining a better understanding of how quickly a project can be completed,
- understanding which activities can take longer (and how much longer) without affecting the overall timeline, and
- knowing where delays to an activity will delay the overall project
Understanding where delays in particular activities will affect the overall project, focusses attention on these time-critical activities.
- Wikipedia on critical path method
- smartsheet's The Ultimate Guide to the Critical Path Method (CPM) - This article has information about the CPM, its advantages, how to calculate it using a variety of tools, and ways to use it.