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Definition of Microsoft Project constraints

  • Article
  • Applies to:
    Microsoft Office Project Professional 2003, Microsoft Office Project Standard 2003, Project Professional 2010, Project Standard 2010, Project Professional 2013, Project 2013 Standard

Summary

Each constraint type in Microsoft Project can be defined as a formula using the following conventions:

ES = Early Start of the activity

LS = Late Start of the activity

EF = Early Finish of the activity

LF = Late Finish of the activity

SS = Scheduled Start of the activity

SF = Scheduled Finish of the activity

CD = Constraint Date

More Information

The following are definitions of Microsoft Project constraints.

  • As Late As Possible: Schedules the task as late as it can without delaying subsequent tasks. Use no constraint date.

    ES=(Calculated)LS

  • As Soon As Possible: Schedules the task to start as early as it can. Use no constraint date.

    (Scheduled)ES=(Calculated)ES + Delay

  • Finish No Earlier Than: Schedules the task to finish on or after the constraint date.

    EF=CD (if Date<EF)

  • Finish No Later Than: Schedules the task to finish on or before the constraint date.

    LF=CD (if Date<LF)

  • Must Finish On: Schedules the task to finish on the constraint date. Once selected the task will not be moveable on the timescale.

    EF,LF,SF=CD

  • Must Start On: Schedules the task to start on the constraint date. Once selected the task will not be movable on the timescale.

    ES,LS,SS=CD

  • Start No Earlier Than: Schedules the task to start on or after the constraint date.

    ES=CD(if Date<ES)

  • Start No Later Than: Schedules the task to start on or before the constraint date.

    LS=CD(if Date<LS)