How to turn off duration auto calculation RRS feed

  • Question

  • I'm trying to create a high-level program plan, that incorporates 10 different project plans. I'm having trouble doing this because the durations are off when I put the start and end dates in a different project file. The reason for this is because each individual project has it's specified non-working days. This would mean that I couldn't incorporate them into a single file because some non working days aren't applicable to other projects. Now I know that I could just create a custom field and name it something other than "duration", but here's the problem with that. I'll use the following example to demonstrate:

    >Program plan: 34 days

      >Summary task 1: 24 days

         >Sub task: 12 days

         >Sub task: 12 days

      >Summary task 2: 10 days

        >Sub task: 5 days

        >Sub task: 5 days

    If these durations were placed in a custom field and I were to change the duration of a sub task in summary task 1, for example, then summary task 1 and program plan durations would not change. I'm sure someone has run into this problem before. Is there a solution?

    Friday, September 6, 2013 6:54 PM

All replies

  • Have you thought about just turning off Calculation for the project?  Project Options > Schedule > Calculation = Off.  Then use F9 to update. 
    Friday, September 6, 2013 7:31 PM
  • As this schedule is for reporting use only, you could create and apply a 7 day calendar or try manual tasks. Obviously with 7 day calendar you would need to enter start then finish dates so the Duration is calculated and it would be different from teh original schedules.

    Rod Gill

    The one and only Project VBA Book

    Rod Gill Project Management

    Friday, September 6, 2013 8:50 PM
  • Program_Scheduler,

    Have you considered creating custom calendars for each project? You could then add the Task Calendar field to your view and select the appropriate calendar for each set of project tasks.

    However, keep in mind that Project only allows one setting for the definition of a Day, Week and month. This will impact the value shown in the Duration field if each project has it's own working hours per day. For example, maybe project 1 uses a standard 8 hour work day but project 2 uses a 7.5 hour work day, project 3 a 9 hour work day, etc. If the duration field shows anything other than minutes or hours (e.g. days), the duration field for those projects whose working hours match the Hours per day option setting will be accurate, all others will be incorrect.

    Hope this helps.


    Friday, September 6, 2013 11:10 PM
  • I don't understand your comment that the summary task and program plan durations would not change.  If the issue is different working versus non-working days (due to holiday schedules), then an option is to create a calculated formula that would show your durations in a common, agreed upon measure - for example, calendar days.  Then summary tasks would then be set to use the formula and would certainly recalculate if you modified a detail task duration.

    If however, as John suggests, the issue is not just different work days but completely different definitions of working time (8 hour "day" versus 10 hour "day") then, I agree with John, show a value that is stable - such as Work (in hours) and Start and Finish dates.

    If you are using different project files and combining them into a master project, the durations will  remain accurate based upon the project calendar set in each project.  The picture below is a master project with two different project files inserted.  The first project "US Holidays" has a calendar where Sept 2 and October 14 are non-working days.  The second inserted project "No holidays" has no non-working days other than Saturday and Sunday.  Both sets of tasks have the same dates but different durations due to the non-working time.

    Sunday, September 8, 2013 2:08 PM
  • Have you thought about just turning off Calculation for the project?  Project Options > Schedule > Calculation = Off.  Then use F9 to update. 
    I Think this is the only way to accomplish what hes asking.
    • Proposed as answer by MorphaToo Wednesday, September 19, 2018 7:52 PM
    Tuesday, September 18, 2018 9:22 PM
  • Easiest.
    Wednesday, September 19, 2018 7:52 PM