How to Calculate Critical Path

The critical path method of scheduling is a very powerful tool for time management within a company. A properly written critical path method chart can help the company determine when raw materials and labor resources are needed for each step along the way to producing a product or service. This can help with managing supply schedules as well as labor issues such as vacations and overtime requirements.

Instructions

1. Determine the steps that are needed to produce the final product that your company is producing. This product could be physical, or it might be a service provided to others.

2. Determine the amount of time needed for each of these steps. Be realistic--think of the time frame under average conditions, not as a best-case scenario.

3. Examine the tasks that you have written down that are necessary to produce the product. Determine the processes that are dependent on other processes to be completed before it is possible to start the task.

4. Create a chart that helps you determine the critical path. Work backwards from right to left, with the right end of the chart being the completed product or service. Draw the name of each step in a circle. Draw the steps that require completion prior to that step in the next column to the left, in a circle as well. Connect the processes with a line--on that line indicate how long the process will take.

5. Complete the chart by continuing to the left until you are down to the first step of the process. This will produce a chart of tasks connected by lines showing the time needed to complete each task. Track the different paths through your chart to determine which path is the longest as far as time required. This is referred to as the critical path and should be used as the estimate for how long the task will take to complete.

Tips & Warnings

• Time estimates can change as you produce the product or service. The critical path chart should be adjusted and edited as you find time estimates that need to be changed. This can even result in a entirely different critical path through the process. Determining the correct critical path is essential to maximizing the resources of your company.

• Any delays to a process in the critical path will delay the final completion of the project. The processes of the critical path should be given special attention to ensure they are completed on time.