Network Sensitivity and the Critical Path

If you’ve been studying the critical path methodology (CPM) and project schedule development, you may have heard the term network sensitivity. Without going into a lecture on constructing project networks with forward and backward passes, I’ll define sensitivity in simple terms.

A project schedule is considered sensitive if the critical path will likely change during project execution. The critical path is simply all the tasks that drive the end date of your project schedule. If your project schedule has multiple critical paths, then your project schedule is considered sensitive. If your project schedule only has one critical path and there is slack among the various tasks, then your project schedule is considered insensitive.

Figure 1 depicts an insensitive network as it only has 1 critical path. (I know it’s a simple 5 task example but explaining sensitivity with a 1000 task schedule can be daunting!)

Network Sensitivity

Figure 1 – Network Sensitivity

Why understand network sensitivity?

Understanding the critical path is useful to know when tracking a project schedule’s performance. In Figure 1 above, if Task 4 is late, the project manager will not have to worry as much compared to Task 1, 2, 3 or 5 as these tasks are on the critical path. If any of these tasks are late, then they will have a direct impact on the project’s end date. Task 4 has some slack or free time before it affects the project schedule.

Understanding how many critical paths and the available slack in the schedule determines how much time the project manager needs to spend specifically managing the critical path. Project managers already have enough work to do resolving issues, managing vendors, and communicating status in addition to the good practice of weekly project schedule control. Monitoring the critical path is just one more value add task that the project manager needs to consider when monitoring project status.

How to find the Critical Path in Microsoft Project 2007

In order to find the critical path in Microsoft Project (and its related sensitivity), please follow my tutorial on how to identify the critical path in Microsoft Project 2007

About Andrew Makar

Professional Cat Herder and an Agile Enthusiast with a keen interest in putting PM theory into actual practice.

2 Responses to Network Sensitivity and the Critical Path

  1. sydcube June 27, 2017 at 6:33 am #

    what is the difference between a gantt chart and critical path analysis

    • Andrew Makar July 6, 2017 at 10:13 pm #

      A gantt chart is a graphical representation of the project timeline.
      Critical path analysis is the technique used to evaluate the project tasks and all the dependencies among the project tasks.
      The linking of tasks creates a network diagram where one tasks needs to finish before another starts. The critical path analysis technique looks for all the tasks that drive the project end date.
      If your project slips 1 day and it is on the critical path, the project end date will slip by 1 day.

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