The critical path is the set of tasks that determine the project end date. For example, a consumer-products company launching a new product will likely have hundreds, if not thousands of tasks and deliverables in the project plan, but the critical path might look something like this:
Design XYZ Component (7 wks) -> Finalize Supplier Agreement (1 wk) -> Build Tooling (20 wks) ->Approve Tooling (3 wks) -> Release to Production (4 wks)
In this case, the longest lead time component in the project will take 27 weeks to get into production once the design is complete and the supplier is selected. Each of the tasks in the above sequence is dependent on the prior task being completed, and together they make up the critical path.
A good project manager always knows what tasks are on the critical path, what tasks could become the critical path if they are not completed on time, and what factors might shorten or extend the critical path.
Oftentimes the tasks that make up the critical path can change as the project progresses. For example, the XYZ component tooling might be completed ahead of schedule, and the launch of component ABC (which has a 17 week tooling lead time) might become the critical path for the project.
Given the complexity of most projects, project management software such as Microsoft Project is the most reliable means of knowing the critical path and the tasks that comprise it an any point in time.
Here are more details related to finding a project’s critical path using a manual approach.