Best way to go about lags/constraints RRS feed

  • Question

  • Hi there,

    I've started scheduling in MS projects a few weeks ago for my employer. 

    I am trying to find a good way to schedule the content as the challenge is that we as a subcontractor have incidental moments that we can do part of the scope within a bigger project. This would mean as an example:

    1-3 October we have work then more on 6-7 October etc. There are gaps in between that I could solve with a lag or with a constraint as far as I know. It's cumbersome to maintain a schedule when this is the case. I would like some advice on a good approach.

    PS we have little information on the scope being performed in between our activities.

    Hope this was clear. Thanks for the help in advance.

    Kind regards,


    Wednesday, October 10, 2018 8:29 AM

All replies

  • Hi P.

    It really depends on your context. If you are a subcontractor working for a client and you are requested to take committments, send I would advice to use constraints so we have a robust schedule and a securized critical path. Note that it is not adviced to have many constraints in your schedule since it can "lock" your project plan: for too many constraints, at a certain time, tasks cannot move anymore.

    If you want a realistic project plan, you could use lag based on your experience and feedback from your subcontractor. You could also add a buffer/contingency task before the major deliverables. 

    Another way to manage it if the gaps are relative to the task durations is to set the lag with a percentage. For example, if you set on task 6 the following predecessor: 5FS+50%, then task 6 will start after task 5 plus a relative lag being 50% of task 5 duration.

    Hope this helps,

    Guillaume Rouyre, MBA, MVP, P-Seller

    Wednesday, October 10, 2018 9:51 AM
  • Hi G.

    Thanks for the help, especially the last comment is new for me and will be useful.

    Thanks again.

    Kind regards,


    Tuesday, October 30, 2018 7:05 AM
  • Hi P,

    As the subcontractor I guess you are told when you have to perform the work? If this is the case then this is really a constraint, and I would enter the start date for those tasks, thereby setting as Start No Earlier Than (SNET) constraint.  I would ALSO add in a dependency perhaps with a lag between the tasks, so that you are made aware that if the predecessor task moves (ie the customer changes the start date of a task) then any successor tasks also move - then you can communicate your new start dates for each task with the customer and get agreement that they are still valid, if not, enter in the new agreed start dates for the successor tasks... 

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

    Tuesday, October 30, 2018 8:58 AM
  • P,

    The scenario you describe is similar to the one in this post:

    You might want to give it a read.


    Tuesday, October 30, 2018 2:09 PM
  • Thanks Ben and John, very helpful.
    Thursday, November 22, 2018 10:13 AM
  • P,

    Youre welcome and thanks for the feedback.


    Thursday, November 22, 2018 2:40 PM