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Resources on a project with Multiple Calendars not calculating correctly RRS feed

  • Question

  • I have a project using resources that work on different calendars, my default project calendar is none. I want to have each resource show with their appropriate work time and duration. I have tried to associate each taks to a unique calendar to no luck, any ideas?

    I am using Project 2010.

    Any ideas would be appreciated.

    Doug

    Friday, May 18, 2012 1:30 PM

Answers

  • Doug --
     
    It sounds like you are assuming that Microsoft Project 2010 calculates the Duration of a task based on the Task Calendar assigned to the task.  I base this on your statement stating that a 10 hour task using a 10 hour calendar would yield a Duration of 1 day.  Microsoft Project 2010 calculates the Duration for every task using the following equation, which I refer to as the Duration Equation:
     
    Duration = Work/(Hours Per Day x Units)
     
    You can find the Hours Per Day value for your entire project in the Project Options dialog near the top of the Schedule page.  Keep in mind that the Hours Per Day value shown in the dialog is used by Microsoft Project 2010 to calculate the Duration of EVERY task in the project.  So, based on the 10 hour task example, here is how the software would calculate the Duration:
     
    Duration = Work/(Hours Per Day x Units)
    Duration = 10/(8 x 100%)
    Duration = 1.25 Days
     
    Notice that the Duration Equation shown above does not factor in the Task Calendar used on the task.  On the other hand, Microsoft Project 2010 DOES schedule the task correctly using the schedule shown on the Task Calendar.  On the preceding example, if you applied a 10 hour calendar as a Task calendar and selected the Scheduling Ignores Resource Calendars option, Microsoft Project 2010 will schedule the task to take one day.
     
    Hope this helps.
     

    Dale A. Howard [MVP]
    VP of Educational Services
    msProjectExperts
    http://www.msprojectexperts.com
    http://www.projectserverexperts.com
    "We write the books on Project Server"

    Friday, June 8, 2012 2:16 PM
    Moderator

All replies

  • ... my default project calendar is none.

    Hi Doug,

    having no project calendar is not an option, so I'm not sure what you mean exactly.

    As you have resources which use different calendars, please create calendars for those resources and assign them to tasks. Create base calendars for your different shift/workloads per day, then assign each resource the respective work calendar.

    Setting task calendars is not an advisable way to handle this situation. And even if you wanted to use them, you still need to check the "Scheduling ignores resource calendars".

    In addition, you seem to have 10 hours work per day for your project as default. This is used to calculate between duration an work. If that is not the setting you want to use, please change it under File (Backstage) / Options / Schedule > Hours per day.

    Kind regards,
    Adrian


    Saturday, May 19, 2012 3:47 PM
  • Adrian,

    There is a project calendar.

    I have tried to select "Scheduling ignores resource Calendar" with the same results.

    What I would have hoped to see was an 8 hour task based on a 8 hour calendar requireing 1 day.

    A 10 hour task using a 10 hour calendar requireing 1 day and the same with a 12 hour task and calendar.

    Any insights or ideas on this would be helpfull.

    Doug

    Friday, June 8, 2012 1:22 PM
  • Doug --
     
    It sounds like you are assuming that Microsoft Project 2010 calculates the Duration of a task based on the Task Calendar assigned to the task.  I base this on your statement stating that a 10 hour task using a 10 hour calendar would yield a Duration of 1 day.  Microsoft Project 2010 calculates the Duration for every task using the following equation, which I refer to as the Duration Equation:
     
    Duration = Work/(Hours Per Day x Units)
     
    You can find the Hours Per Day value for your entire project in the Project Options dialog near the top of the Schedule page.  Keep in mind that the Hours Per Day value shown in the dialog is used by Microsoft Project 2010 to calculate the Duration of EVERY task in the project.  So, based on the 10 hour task example, here is how the software would calculate the Duration:
     
    Duration = Work/(Hours Per Day x Units)
    Duration = 10/(8 x 100%)
    Duration = 1.25 Days
     
    Notice that the Duration Equation shown above does not factor in the Task Calendar used on the task.  On the other hand, Microsoft Project 2010 DOES schedule the task correctly using the schedule shown on the Task Calendar.  On the preceding example, if you applied a 10 hour calendar as a Task calendar and selected the Scheduling Ignores Resource Calendars option, Microsoft Project 2010 will schedule the task to take one day.
     
    Hope this helps.
     

    Dale A. Howard [MVP]
    VP of Educational Services
    msProjectExperts
    http://www.msprojectexperts.com
    http://www.projectserverexperts.com
    "We write the books on Project Server"

    Friday, June 8, 2012 2:16 PM
    Moderator
  • Dale,

    Thank you for finally bring this issue to a close for me.

    Regards,

    Doug MacNEIL

    Monday, June 18, 2012 12:35 PM
  • Doug --
     
    You are more than welcome for the help, my friend!  :)
     

    Dale A. Howard [MVP]
    VP of Educational Services
    msProjectExperts
    http://www.msprojectexperts.com
    http://www.projectserverexperts.com
    "We write the books on Project Server"

    Monday, June 18, 2012 12:57 PM
    Moderator
  • I'm borrowing this thread since i believe I'm struggling with the same problem as Doug.

    I'm not sure I understand the logic behind "Hours per Day" and that it's used for calcualting the duration of EVERY task in the project. Then what is the point with resource calendars? If I assign a 16 hour task to a 2-shift resource (i.e. 16-hour days), I would like the duration to be one day. And if the same task is assigned to a 1-shift resource it should take 2 days.

    Where am I going wrong?

    Tuesday, October 16, 2012 4:15 PM
  • Greymane --
     
    Hours Per Day is used to calculate the Duration of tasks.  Microsoft Project does not factor in the resource calendar when calculating the Duration, but it DOES factor in the resource calendar when scheduling the task.  That is simply the way the software works, and there is no way to change it.  Furthermore, although I understand your argument, I do not work for Microsoft, so I cannot comment on why they designed the software the way it is designed.  Hope this helps.
     

    Dale A. Howard [MVP]
    VP of Educational Services
    msProjectExperts
    http://www.msprojectexperts.com
    http://www.projectserverexperts.com
    "We write the books on Project Server"

    • Proposed as answer by Greymane Wednesday, October 17, 2012 8:48 AM
    Wednesday, October 17, 2012 12:10 AM
    Moderator
  • After sleeping on it I realized (hopefully correctly!) that I could insert an extra column with a formula calculating the duration with resource calendars considered. The Duration is not used for anything but "for show" - scheduling will not be based on this, as you pointed out, Dale.

    Wednesday, October 17, 2012 5:45 AM
  • Graymane --
     
    It sounds like you got a good nights sleep, which led you down the path to true knowledge.  Yup, you sure can create a custom Duration column for your scheduling and display purpose.  Way to go, my friend!  :)
     

    Dale A. Howard [MVP]
    VP of Educational Services
    msProjectExperts
    http://www.msprojectexperts.com
    http://www.projectserverexperts.com
    "We write the books on Project Server"

    Thursday, October 18, 2012 1:32 AM
    Moderator
  • I believe I've somehow deviated from the True path, Dale. I feel utterly confused and lonely..

    I want to manually set a duration (to my Fixed Work task) and see the Units change to accomodate the change (keeping the "Iron equation" correct). Problem 1: Units don't change. Problem 2: if I select two tasks with the same Work, setting the same Duration, the gantt bar would be different between the two if the resource calendars are different. I want the gantt bar (time between Start and Finish=real duration) to be the same for the two tasks - only Units should be different.

    So I figure I can't use the Duration field if I have multiple resource calendars. What do I do instead?


    • Edited by Greymane Thursday, October 18, 2012 1:51 PM
    Thursday, October 18, 2012 1:42 PM
  • Greymane --
     
    You have not deviated from the Truth Path, my friend.  Instead, you got blindsided by a new feature in Microsoft Project 2010.  This new feature is part of a bug fix for a bug that was in every previous version of Microsoft Project.  Do the following:
     
    1.  Open the project in question.
    2.  Apply the Task Usage view.
    3.  In the Task Usage view, insert two additional columns:  Assignment Units and Peak.
    4.  Select the Fixed Work task where the Units did not change when you changed the Duration
     
    Notice that the Assignment Units column for the selected task contains the ORIGINAL Units value.  Notice also that the Peak column for the selected task contains the NEW Units value.  The software used the Peak value when you changed the Duration of the Fixed Work task, so the task IS scheduled correctly, even though you did not see the Units value change.  So, you were right all along, even though you did not know it!  :)  Hope this helps.

    Dale A. Howard [MVP]
    VP of Educational Services
    msProjectExperts
    http://www.msprojectexperts.com
    http://www.projectserverexperts.com
    "We write the books on Project Server"

    Friday, October 19, 2012 12:58 PM
    Moderator
  • OK, now I see! The reason for me not seeing the Units change was that I hadn't applied the Task Usage view - I had included a Peak column in the gantt-view, which doesn't contain the same value as the "Task Usage Peak".

    Thanks!

    Tuesday, October 23, 2012 10:14 AM
  • Greymane --
     
    Well, done my friend.  And you are more than welcome for the help!  :)
     

    Dale A. Howard [MVP]
    VP of Educational Services
    msProjectExperts
    http://www.msprojectexperts.com
    http://www.projectserverexperts.com
    "We write the books on Project Server"

    Tuesday, October 23, 2012 12:15 PM
    Moderator