Purpose of '% Complete' field RRS feed

  • Question

  • I'm almost embarrassed to ask, but what is the purpose of the '% Complete' field?  The mouse-over on the field heading states that it is "...the percentage of the task's duration that has been completed."  

    Therefore, is it simply a field to indicate what percentage of a task's expected duration has elapsed?  e.g. if we have a task expected to take 10 days and 5 days have passed, % Complete = 50%?  If it's this simple, why not have it auto-update every time the project file is opened?  What is the point of having to manually enter values in '% Complete' or 'Actual Duration' to update this field?  And, in the example above, why would someone ever want to enter anything other than 50%, e.g. 75%, if only 5 days of the tasks expected 10 days of duration have elapsed?

    For a seemingly simple field, it raises a lot of questions as to why one would ever want to use it...  '% Work Complete' seems a lot more intuitive, yet '% Complete' seems integrated into more base functionality, such as progress bars on Gantt charts.

    Thoughts anyone?



    Wednesday, September 17, 2014 4:51 PM


All replies

  • Found an answer suitable for my own curiosity...

    I guess I can see some value in tracking % Complete for EV metrics...  And I suppose it is a very simplistic measure of how things are progressing.  Although I still can't imagine why you would ever put anything in the field other than the percentage of days in a task's duration that have elapsed.


    • Marked as answer by jjmclell Wednesday, September 17, 2014 7:43 PM
    Wednesday, September 17, 2014 7:43 PM
  • Fyi, i never (as you say) put anything in the field.  I collect and record (after baselining) the [Remaining Duration] and let Project to the heavy lifting to computer [% Complete].


    Wednesday, September 17, 2014 11:24 PM
  • This is one of those things which seems obvious and simple, but it is actually quite subtle and worth thinking hard about.

    Yes, you are correct that it measures actual duration divided by total duration and of course total duration = actual+remaining. Understanding that, and knowing that it has nothing to do with the progress of the task itself, is an essential first step.

    In the first part of your question you imply that 5 days after a 10 day task was scheduled to start, it should be 50% complete, and so it should be auto updated without your input. But this is only true if two things occurred, and they are that the task did actually start exactly when it was scheduled to start, and also that it has been in continuous progress ever since, in which case it has an actual start and an actual duration of 5 days.

    What if the task actually started 2 days after it was scheduled to start, used 1 day of the 10 day duration and was then interrupted? You would have to input the actual start date,then the actual duration of 1 day,and the move the remaining 9 days into the future, and the % complete would be 10%. So your intervention is essential.

    Parts of your question imply that the % complete field is "used" in some way, or that you are supposed to enter something into it. Why do you say that?

    I never, ever, enter anything into it, and I always advise never to. There is never any need to. It is simply calculated by MSP.

    • Marked as answer by jjmclell Thursday, September 18, 2014 4:22 PM
    • Unmarked as answer by jjmclell Thursday, September 18, 2014 4:26 PM
    Thursday, September 18, 2014 4:41 AM
  • I suppose the reason I'm implying that the % Complete field is 'used' in some way is because I'm assuming it conveys some kind of important information to the typical PM.  For myself, relatively new to PM, I see how the figure's calculated and I wonder what value it serves having that figure at my disposal.  It's not even as though it's one of the more obscure data fields in MSP - it controls the progress bar on the Gantt chart, so when I use the Gantt chart for reporting purposes, I have a progress bar that, in my opinion, is not intuitive and would be better reflected by % Work Complete.


    • Edited by jjmclell Thursday, September 18, 2014 4:42 PM
    Thursday, September 18, 2014 4:41 PM
  • Well, I suppose your assumption that it conveys important information is incorrect. Or at least, it conveys what it is, and no more. Maybe you should ask the typical PM what he gets out of it. If he is unaware of what it means or measures and/or if he is reading something into it that isn't there, then that's hardly the fault of an innocent number.

    The % Complete field is no more or less obscure than any of the others. It's just one of them, and it is usually well and truly buried in the tracking table, out of the way. The problem occurs when people insert it into the entry table and start putting numbers into it (based on what?).

    The task bar is not like a thermometer. Its length is duration on a timescale. The progress indicator on it can't (sensibly) be anything except duration, and that duration is from the actual start to the complete through date. You can see this in the definition of the bar in format, bar styles. You can't (sensibly) overlay a progress bar expressed as % work on top of a bar which is duration. You may as well try to overlay a "progress" bar which is the cost represented as a fraction of the duration. It's length would be:

    duration1 = (actual cost/total cost) x duration.

    You could use this fraction of the duration in a formula to calculate a custom start1 and custom finish1, where start1 = actual start and finish1 = actual start + duration1. Then you could format a thin bar style to go from start1 to finish1. So although its technically possible (I've done it) it is a lot of effort for no useful result.

    The thin black progress bar is most sensible when it is seen as duration and nothing else. It is perfectly meaningful and intuitive if you know what it means, and nonsense if you think it means something else.

    Intuition is over-rated, it is so often wrong. For example, intuition must be what makes people think that planning backwards from a finish date is a good idea.

    In what way do you use 5 complete for reporting? I see almost no use in reporting progress in terms of % complete, but everyone asks for it. I guess it gives them comfort but it does not give them much information, except what they read into it.

    Thursday, September 18, 2014 9:41 PM