Microsoft Project and Earned Value and TCPI – 4294967295

BY: Collin Quiring

Just a quick note on an “error” within Microsoft Project where the value is “4294967295” in the TCPI field.  This is actually the numerical equivalent of “NA”.  Sometimes this is used in formulas to find when a field is “null”.  For example, some folks will put something like ‘IIf(ProjDateValue([Baseline Finish]) = 4294967295, “No Baseline”, “Baseline Set”)’   That is probably the best formula when you are in a multi-language environment and using this one is probably better in a ‘IIf(ProjDateValue([Baseline Finish] = ProjDateValue(ʺNAʺ) , “No Baseline”, “Baseline Set”)’   in an English environment.

Now that you know where/why that number 4294967295 might be used, let me explain what we have been seeing in Project for a while now – in the TCPI field.  (It is elsewhere as well, but since I was explaining this to a class in Earned Value, that is where I am coming from in this case.)  TCPI shows the ratio of the work remaining to be done to funds remaining to be spent, as of the status date.  For the TCPI based on BAC (describing the performance required to meet the original BAC budgeted total) use this formula: TCPI = (BAC-EV) / (BAC-AC)   For the TCPI based on EAC (describing the performance required to meet a new, revised budget total EAC) use this formula: TCPI = (BAC-EV) / (EAC-AC).

So, now to the “error” which is NOT really an error – getting a value of 4294967295 in the TCPI field.  The answer is relatively easy, when a task has been 100%, the TCPI is “NA”.  And, this is a numerical field in our environment so the system puts in the Microsoft equivalent of “NA” and puts in the 4294967295 number into that field.

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