If you want things done as fast as possible, then the Critical Path Method is a great project management method to consider. This versatile and effective system was first put into practice in 1940, during the infamous World War II Manhattan Project. Since then, the critical path method has been used in anywhere from construction to software, and research to product development.

To get started with the Critical Path Method, you need to do four things:

  • List all activities in the plan
  • Plot all the activity durations
  • Draw the dependencies between activities
  • Mark milestones and deliverables

Once you have all this information, the Critical Path Method calculates the longest sequence of planned activities from the start to the end, hitting all significant milestones in between. It takes into consideration the earliest and latest times that each activity can start without making the project longer.

“Critical” tasks are those whose deadlines directly impact the project timeline.  “Float” tasks are those that can be delayed without extending the project, and are considered non-critical paths that run in parallel to the critical path.

Crash Duration

“Crash duration” means the shortest possible time an activity can be done. This usually involves assigning more resources to the task than normal in an effort to get it done much faster.


The Critical Path Method also takes resources into account, and can split applicable tasks between team members if they’re not co-dependent. Team members working in parallel can drastically reduce the overall project time.


It’s important to be flexible when using the Critical Path Method, especially given the nature of the system. Any change or delay will directly impact the project timeline, and therefore the plan will have to be revised. The good news, however, is that because you’ve measured each task’s duration, you can reasonably estimate a new timeline with some accuracy. In fact, there is a form of postmortem analysis called the As Built Critical Path that looks into the differences between the original planned schedule and the one actually implemented, and why the delays happened.

Planning for Success