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How to Calculate Critical Path in Project Management

Critical path in project management refers to the sequence of tasks that are critical to your project completing on time. It’s the longest series of tasks within your project, which means that if you have a delay on any of those tasks, it will push out your project end date. Tasks that aren’t on the critical path may be able to suffer a delay without impacting your overall schedule.

Many scheduling tools will automatically identify your critical path for you, as long as you built the following three key elements into your schedule:

  1. All project tasks with start and end dates
  2. Task durations
  3. Task relationships or dependencies

How to manually calculate critical path in project management

If you’re not using project management software, or you just want to double check things for yourself, here is how to calculate critical path in project management:

  1. Identify all of your activities or tasks, their durations, and their relationships.
  2. Build a schedule network diagram, which is a visual sequence of how your tasks interrelate.
  3. Now you need to identify all possible paths through the diagram.
  4. Next, calculate the duration or length to complete each path by adding up the durations of all tasks along that path.
  5. Identify which path has the longest total duration. That is your critical path.

The benefits of calculating critical path in project management

Once you identify the critical path of your project, it helps aid your decision making and ensure the success of your project because you can now quickly understand if a task delay will impact the overall project or not, and react accordingly. It allows you to prioritize activities on the critical path, and reschedule priorities not on the critical path in order to spread out resources.

Further reading: