Influence of constraints and FF links on leveling

[Thomas V]

Hi everyone,

I've come across a situation where I'm a little puzzled as to how
resource leveling comes a particular conclusion. It involves Finish to
Finish relationships and constrained tasks

Here are an example of the schedule after Resource Leveling: Leveling
delay on Task3 is set at 11edays.
Name Dur. Constraint Type Start
Finish Res. Predecessor
================================================================
Task1 05 days Start No Earlier Than 17-Dec-07 21-Dec-07 John
Task2 40 days As Soon As Possible 27-Nov-07 21-Jan-08 Mary
Task3 30 days As Soon As Possible 24-Dec-07 01-Feb-08 John 2FF
+2 days
Other relevant info: MSP 2003, Leveling options: Allow Split=yes

I would have expected Automatic leveling to split Task3 such that it
starts as soon as possible while respecting the FF+2 relation to
Task2. What happens though is that Taks3 gets delayed to start only
after Task1 has completed. Seems to me that this breaks the ASAP
constraint.

Interestingly enough, if I inverse the FF relationship such that Task3
is the predecessor then Resource Leveling does split Taks3.

Am I missing something or have I encountered a bug of some sort?

Thanks for the help.
Thomas

 

[Jack Dahlgren]

If John is assigned at 100% then of course task1 and task3 can not be done
at the same time. So project delays task3 until it can start. This is what
leveling is supposed to do. And yes, leveling does break the ASAP
constraint. It is designed to do that. If it didn't then tasks would not be
leveled.

-Jack Dahlgren

 

[Thomas V]

What I don't get is why MSP did not split the task such that John
starts work on the project's start date, in this case 27 Nov. There
seems to be no logical reason for it not to do so.