Error when assigning resources RRS feed

  • Question

  • Good evening,

    I teach MS Project and found that when assigning resources to tasks, Project is very unforgiving. If you make a mistake after entering a resource the task duration could change inadvertently. If you want to go back and undo your mistake, it will allow you to correct the resource allocation, BUT the task duration will not go back to what is supposed to, or even change to whatever it is supposed to. Not sure why this is the case, but I would like someone to help figure out how to be able to tell the students that they can assign the resources and undo it without being concerned about having serious mistakes in the schedule as they move on.

    Thanks in advance for your help.

    Saturday, February 25, 2017 2:54 AM

All replies

  • SamirBA,

    What version of Project are you using? Is it updated with the latest cumulative update?

    Please give us more details about what you are seeing. For example, is the task fixed work, fixed duration or fixed units? Is it auto-scheduled? Under what conditions does the Undo not set the task parameters back to what they were before the assignment? For example, did the task already have a resource assigned and then you came back later and assigned another resource? Had work been started on the task?


    Saturday, February 25, 2017 3:17 PM
  • If a task already has resource assignments, then it has work. If you then start changing ("undo your mistake") the resource assignment units or the duration, or the work, or all three, MSP responds according to the task type and the effort driven setting which are active when the change is made.

    There are three task types, fixed units, fixed duration, fixed work, and for each one effort driven can be on or off, but for fixed work task type, effort driven can only be on, so there are 5 possible combination of the settings and 5 possible outcomes.

    The important relation is work= effort x duration

    One can change and force a change of one of the others, but not both. One has to be "fixed", like this.

    8 hours = 100% x 1 day

    8 hours = 50% x 2 days

    8 hours = 200% x 0.5 day

    You have not said what the "mistake" is that you were trying to fix but I suppose that maybe you had one resource assigned and later came back to add another, and the duration changed and the work did not. This suggests the task is fixed units and effort driven on. This was the default in MSP2007, and it did tend to confuse people a bit and MSP2010 the default is now fixed units, effort driven off, so that if you add the resource the work increases and the duration stays the same. But the default is not important because what is important is getting the result you want.

    Sometimes you can end up chasing your tail if you try different settings and randomly change duration or assignments or work. Just delete the resources from that task and start again.

    Students of MSP should be introduced to this and made aware of it very early, and need to be really comfortable with it to head off confusion.

    Saturday, February 25, 2017 11:26 PM
  • As a suggestion, use some of the spare fields (DurationX) to capture initial assumptions.  Those fields will not change and you have a stable field for comparison.
    Sunday, February 26, 2017 5:46 PM