Honestly, I would say that the root cause here is that only one slide is created for such a critical topic as CPM. It is unfair. If there would be one good example with details how to create a network diagram, then there was no room for such a flaw.

Hi Cornelius,

a) A, B, C, D, F nodes use formula EF = ES + Duration - 1. E node uses formula EF = ES + Duration. Both formulas are ok, but please use it consistently for all nodes.

b) The slack time, also known as float time, for an activity is the time between the earliest and latest start time. Critical activities, activities on the critical path, will always have zero slack.

Slack = LF - EF
Slack = LS - ES

The only node on your diagram that fulfill both formulas is D. The rest look incorrect. Let me refer to Figure 6-16 in PMBoK guide (6-th ed).

Regards,
Ruslan.

Hello Ruslan,

Would you please explain why you think the network diagram we used is wrong? I'd like to understand your reasoning behind the changes you have applied to it.

Thank you!

There are so many things wrong on the diagram in L06.03.
I have also attached the example of correct diagram.

Hope it will make your PMP course better.