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anjseattle's avatar
anjseattle
Copper Contributor
Dec 05, 2023

MS Project Standard 2021 calculating duration incorrectly

All of my tasks are auto-scheduled. ALL of my tasks are calculating in DAYS even though the Duration  units show as weeks, months, etc. Why are duration units showing up incorrectly? In my previous desktop version THIS DID NOT HAPPEN, I was able to enter any unit and MS Project would include them all & calculate durations correctly. So frustrated - this is throwing all of my old schedules out of whack and the incorrect units is very dangerous.

 

  • Hi anjseattle 

     

     

     

    As Dale pointed out, you most likely have 8 hours in the Hours per week option of your project.

    If so, I recommend that you follow the following steps to avoid losing part of your work, if the values shown in the Duration column, at the task level not summary task, are correct:

     

    1. In the tasks table, clear all active filters and expand all summary tasks.
    2. Select and Copy the Duration column (to clipboard)
    3. Change to 40 hours, the Hours per week option for your project.
    4. Paste the Duration column.
    5. Put all tasks in Auto Scheduled Task Mode.

     

    N.- The final result of the dates will depend on the different restrictions of the Finish no Earlier Than type, which apparently many of the tasks shown in your screenshot have. I remind you that one of the ways to eliminate them is to leave Type in As Soon As Possible.

     

    I hope you find it useful.

    Ignacio Martín

  • anjseattle --

    Well, since you did not include any screenshots, we can only guess what is going on. Since you indicated your have been planning in months, were you aware that in Microsoft Project, a "month" is the equivalent of 20 working days. This option is specified in the Project Options dialog on the Schedule page. It is the Days Per Month option.

    If you really want our help, please share a screenshot or two so we can see what is going on in your project. Hope this helps.
    • anjseattle's avatar
      anjseattle
      Copper Contributor

      Dale_HowardMVPhere is a screenshot; notice that the durations showing days are correct, but the ones showing weeks are not - where "12 weeks" is shown, it is calculating to 12 days. These are fixed duration tasks, no resources, standard 40 hour workweek.

       

       

       

      • Ignacio_Martin's avatar
        Ignacio_Martin
        Iron Contributor

        Hi anjseattle 

         

         

         

        As Dale pointed out, you most likely have 8 hours in the Hours per week option of your project.

        If so, I recommend that you follow the following steps to avoid losing part of your work, if the values shown in the Duration column, at the task level not summary task, are correct:

         

        1. In the tasks table, clear all active filters and expand all summary tasks.
        2. Select and Copy the Duration column (to clipboard)
        3. Change to 40 hours, the Hours per week option for your project.
        4. Paste the Duration column.
        5. Put all tasks in Auto Scheduled Task Mode.

         

        N.- The final result of the dates will depend on the different restrictions of the Finish no Earlier Than type, which apparently many of the tasks shown in your screenshot have. I remind you that one of the ways to eliminate them is to leave Type in As Soon As Possible.

         

        I hope you find it useful.

        Ignacio Martín

  • D_Casey's avatar
    D_Casey
    Copper Contributor

    I am having a similar problem. My "start" and "finish" dates are not calculating correctly. Here is a screenshot of what I am getting. 

    What I want to happen is for the duration to drive the finish dates. E.g., if a task duration is 30 days and starts January 1 I want it to finish January 31. I've input 30 days as the "duration" but even if I use a 24-hour calendar it is calculating the finish dates wrong. I've tried adjusting the standard hours in a day and in a week, the standard days per month, but it will not calculate correctly. Any ideas?

    • John-project's avatar
      John-project
      Silver Contributor
      D_Casey,
      Simple solution to your issue. If you want you schedule to be in calendar time instead of working time, enter duration values as 30ed, meaning 30 elapsed days.
      John
    • Ignacio_Martin's avatar
      Ignacio_Martin
      Iron Contributor

      D_Casey 

      Hello Casey

       

      In the case shown, the results seem correct, if the calendar weekends (Saturday and Sunday) are non-working days.

       

      As Jhon just commented, you can define the calendar as normally as your project requires, and add a letter "e" (elapsed) in front of the letter d for day in the number of days of duration of the task, since Project considers that duration as natural time or elapsed, without considering the non-working time of the calendar.

       

      For example, a Duration of 1ed=24h and 90ed=90x24h regardless of calendars and hours per day.

       

      You must keep in mind that in this type of elapsed time duration, when assigning a resource, it will work the entire time of the task (24 hours), regardless of its calendar.

       

      By the way, for Project, a task with a duration of 30 working days, starting on January 1 early in the day, if all days are working days, ends on January 30 at the end of the day.

       

      On the other hand, if the duration is of type ed (elapsed time), the task will end at the same time it started.

       

      I also recommend that you provisionally observe the date times by changing the format to Wed 01/28/09 12:33 in the General tab of the Project Options.

       

      And one last trick, perhaps simpler than all of the above: select the task in Manually Scheduled Mode, manually enter the Start and End date you want, and select the task again in Auto Scheduled mode.

       

      I hope I've helped.

      Ignacio

       

       

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