Critical Path Method or, as it is endearingly known, CPM is the most important tool to keep your projects on track. Do you remember Network Diagrams? Every network diagram has a Critical Path.
Critical Path
Critical Path is basically the longest string of activities in the network diagram. So if you add durations of all the activities on all the paths in your network diagram, the one with the highest duration is the Critical Path.
The most important aspect of critical path is the fact that a delay in any of the activities on the critical path is going to delay the entire project. Read the previous line again. Isn’t it obvious that knowing your project’s critical path is, well, quite critical!
This also means that activities not on the critical path can get delayed without impacting the project. This definitely gives you a fair idea of what’s urgent and what can wait. Conversely, this also gives you a fair idea of what activities must finish early for the entire project to complete ahead of schedule.
How to find the Critical Path?
Now it is quite obvious that on real world projects you would be using a software like Microsoft Project to find out the critical path but the software uses the same calculation that we are going to learn here.
Do refer to the video for step-by-step calculation of the critical path in the example below,

Clearly, ACFG is the critical path with the highest duration of 13.
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