calculate start date as late as possible RRS feed

  • Question

  • Dear All

    I have the following question....

    I have a task ("Qualification") which cannot start before another task ("handover") is completet, so I put an end-to-start constraint from handover to qualification.

    Another precursor is the task ("write plan") which has to be done before "Qualification"

    I want to automatically calcuate the start date of "write plan" as late as possible so that the task is done just in time when "handover" is done and "qualification" can be started.

    can anyone help? thanks, Oliver
    Sunday, December 30, 2018 7:17 PM

All replies

  • Oliver,

    In addition to your existing logic, I suggest using a dummy milestone called "JIT Finish Qual Plan."  Make it a FS successor of the Handover task and a FF predecessor of the "Write Plan" task.  ("Write Plan" should also have a legitimate Start predecessor to avoid dangling logic.)

    An alternate approach is to use an early constraint on "Write Plan" as needed to mimic the zero-free-float behavior you want.  (I wrote a macro some years ago to automatically manage such constraints, but I don't use it.)

    The dummy milestone leads to good dates and proper logic flow in most practical cases.  Whatever you do, avoid the temptation to use Start-to-Finish relationships to get the (early) dates you want.  The resulting late dates (and Slack) will almost always be wrong. 

    Good luck, tom

    Monday, December 31, 2018 2:30 PM
  • Set the constraint type of the Write Plan to be As Late As Possible (and ensure the tasks are auto scheduled).

    Ben Howard [MVP] | web | blog | book | downloads | P2O

    Tuesday, January 1, 2019 9:25 PM