Calculating Critical Path - Can't figure out LF

[whazzzzzupp17]

Hello, I'm having some major problems trying to calculate this and been working on determine LF all day.

I tried Index match to lookup all the predecessors, but I think I need to us MINIF(), but it keeps outputting 0

ES	EF	LS	LF	Predecessor	Duration
2/1/21	2/1/21	=LF - Dur
2/2/21	2/2/21	=LF - Dur		1
2/3/21	2/8/21	=LF - Dur		2
2/2/21	2/4/21	=LF - Dur		1
				4

 

[6StringJazzer]

Calculating LF is not simple because you have to work forwards through dependencies and calculate slack, and determine what is the critical path. In this example, the critical path is 1 -> 2 -> 3. Task 4 is not on the critical path because it has 4 days of slack. To calculate slack you have to work through all the possible forward dependencies on all tasks. I have done this in an Excel VBA version of Microsoft Project, and I just don't think a general solution can be done simply with formulas.