Our Program Management office is interested in identifying tasks where the projected execution differs from the planned execution. MS Project's "Duration Variance" field calculates the difference between the baseline duration and the planned duration
( ( [Baseline Finish] - [Baseline start] ) - ( [Finish] - [Start]) )
That doesn't contain any information about the execution variance. *Aside: I know that I could simply ignore [Actual Start] / [Actual Finish], and treat the Baseline as Planned and the Start/Finish as the execution, but I've got legacy assumptions to deal with. *
I tried to build a custom field [Projected Duration] such that
[Finish] - [Actual Start]
I also tried
ProjDateDiff([Actual Start],[Finish])
Aside: I'm aware that I would need some error checking to deal with Actual Start = NA, but let's solve the simple problem first
Both of those are returning "0" duration for tasks with known values for both fields.
How do I calculate execution variance?