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Definition of Microsoft Project constraints

Article ID: 74978 - View products that this article applies to.

This article was previously published under Q74978

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)

For more information on Contraints, please see the "Microsoft Project for Windows Reference" or query on:

winproj and constraint