two different cost calculations using same data

[AJS]

I need help! I have a project file in which I have two identical (as near as
I can tell) tasks, assigned the same resources, both fixed duration
effort-driven, and I get two different cost calculations on the Gantt chart.
What could be the cause of that? Again, I've checked everything in the Task
Information dialogue and all appears to be identically configured yet one
task's cost is way off. Any thoughts?

 

[Dale Howard [MVP]]

AJS --

Do you have a Fixed Cost associated with the more expensive task? Do you
have a Cost/Use amount specified for the resource assigned to the more
expensive task? Have you applied Actual Overtime Work on the more expensive
task? Let us know.

 

[AJS]

I have now done an Excel calculation and know that the more expensive task is
the correct one. There are no fixed costs, cost per use, or actual overtime
expenses on either the more expensive or less expensive tasks. I cannot
imagine how the incorrect task's calculation can be 40% or so less than
accurate.

 

[AJS]

Well, here's what I've done since my last post. After concluding that the
hours worked must be wrong, I selected Windows Split Screen so I could see
the hour calculations for each resource and, sure enough, for one of the
resources (Technicians[300%]) the hour calculation was way off even though
the Duration was correct. If I put '0' in the duration and then reenter the
correct Duration it recalculates it correctly, and the Cost is then correct.
I have the program set up to do automatic calculations and I was pressing f9
anyway, so that's not it. Still don't understand it, it seems like a flaw in
Project, but I can at least get to the right answer.