I have several calendars, one for 365 days a year without holidays, for tests like microbiology incubation, another for 7 days a week but allow holidays used during crunch time, and 5 days a week, a normal one.



I believe this causes problem with my critical path calculation, here's what happened -

Task 1 uses 365 days calendar, takes 5 days from Mon-Fri,
Task 2 follows and uses 5 d/w calendar, takes 2 days from next Mon-Tue.

The critical path calculation shows task 1 has 2 slack days, not in critical path

I tried to use Options>Calculation and set "Tasks are critical if slack is less than or equal to" as 2 days, but it shows too many tasks

Anyone has any suggestion on how to show the true critical paths Thanks for your advice in advance.

I'm not sure I follow, because it seems to me that Task 1 should not be in the critical path (if you started Task 1 on Wed instead of Mon, it would not change the start date of Task 2, meaning Task 1 has 2 days of slack).

If it is that you need for the task to finish during work hours Friday, maybe try setting a FNLT constraint on Task 1 for Friday and see if that helps.

That was my point, task 2 can not move ahead even though task 1 still has 2 days slack. As a result, the critical path filter won't show task 1 and any critical path tasks before task1. The whole project shows task 2 as the only one task in the critical path, that's it.

The early/late start/finish date calculation for the slack doesn't work under 2 different calendars. May be it should be based on the more restrictive calendars between the two task? Any article discuss this special case? Need advice on the alternatives in MS Project?

BTW, what is FNLT?

I respecfully disagree. The critical path filter won't show task 1 because it is not critical... If something goes amiss, and you don't start task 1 on time, there is no affect on task 2 or on the project finish date.

Critical means that if it finishes late then some other task or the project finish date will be affected. Task 1 is not critical; if you don't start it until Tuesday, it won't hurt anything.

Critical does not mean that the next task cannot start early. It means that this task cannot get behind.

FNLT is Finish No Later Than constraint.
Instead though, add 2 days of lag time to Task 1. This should make it critical.

Hi, Kimberly -

My problem is the schedule shows Task 2 as the only task in the critical path.

I want to know if there is any alternative in MS Project to show Task 1 in critical path even though it has 2 days slack time, Task 2 can not move any further ahead.

If no other alternative, I'll have to add a 2 day dummy task and watch it, or go back to option 2 days.

Did you try adding 2 days of lag to Task 1?

If you're not sure how... Double-click on Task 1. Go to the Predecessors tab. Click in the Lag field and type a 2 and press Enter.

I hope this will get it!

Hi, Kimberly -

Thanks for your advice. I can do that.

Andre