Primevera P6 Conversion to MS Project Duration Issue


  • A schedule that I have taken command of was initially created in MS Project. The schedule was first created with all activities with 5x8 work weeks where in actuality design work had 5x8 work weeks and construction is working off of a 6x11 schedule (12 hour work day with 1 hour taken out for breaks = 11 hours). After some time, a new calendar was created to differentiate between the different types of work (5 days per week/6 days per week). At this point, I took over and converted the file to run on Primevera P6 where I began to resource load the activities along with a few other things (non-schedule related). After converting back to MS Project (at the request of The Owner), my durations are not correct even though they were before the conversion. What happens is when I go to File > Options > Schedule and see the hours/day are at 8 hour days/5 hours per week, all of my activities with that calendar are correct but the other activties with the 6x11 calendar are higher by a factor of 1.375 (11/8). If I go to File > Options > Scheudle and change the hours/days to 11 hour days/6 days per week, my construction durations are correct but now my design hours are lower by a factor of 1.375.

    Any ideas on what is happening? I have pin-pointed it to the default hours/days, but after messing around with some settings, I have not been able to figure out how to solve this issue.



    Monday, May 15, 2017 12:46 PM

All replies

  • That's because P6 calculates durations differently.

    In Project if I have 2 tasks, each 5d duration and both 40h/w calendars then change one task to a 60h/w calendar, that task is still a duration of 5d but the finish date is earlier.

    In P6 when I change calendars for a task P6 changes the duration as well as the finish date. So you need to convert activities back to 40h calendars before exporting to Project.

    This is something I believe Project is better at. In P6 to understand how many hours there are in a task you have to know the hours in the calendar as well as the duration. Not simple and a pain in the brain!

    Rod Gill
    Author of the one and only Project VBA Book and VBA developer.

    Saturday, May 18, 2019 12:27 AM