Critical path - Have I misunderstood the logic?

[PBNZ]

Hi All

We are looking to use the critical path functionality but am not sure why its behaving a certain way. 

If you look at this screenshot, why doesn't Task 1 appear on the critical path when it is earlier than task 3? I understand task 3 is longer however shouldn't it provide us with the earliest start point, Task 1? 

Thanks!

[drbronson]

It appears Task 1 is in the Critical Path Line; They both start on 22-02-0023 (The green vertical line).

[Pall Sigurdsson]

It's a bit difficult to analyze this without seeing the dependency and constraint type columns but what appears to be the reason task 1 is not part of the critical path is that it is not on the patch which directly affects the finish date. It's on the patch which leads to Task A and there appears to be some slack between task A and the Go-live milestone. To determine the critical path, the system looks at the last task or milestone and traces itself back from there, based on the durations, dependencies and other constraints. Sometimes adding constraints such as lag between tasks may make the critical path look fragmented.