Constraint

Constraints are applied to your tasks to impose restrictions on the way the task's start and finish dates are calculated. Often, they represent real world conditions. Examples:

  • The last date to submit a bid is 20th May 2018
  • Application testing can begin only after the phone is available in the market on 1st October 2020

NameAbbrreviationDescription
As Soon As PossibleASAPSchedules the task to begin as early as possible. This is the default constraint for new auto-scheduled tasks. For stand-alone tasks, this will always schedule tasks from the project's start date.
As Late As PossibleALAPSchedules the task as late as possible, without delaying subsequent tasks. For stand-alone tasks, this will always schedule tasks backwards from the project's planned finish date.
Start No Earlier ThanSNETSchedules the task to start on or after a specified date. Use this constraint to ensure that a task does not start before a specified date.
Start No Later ThanSNLTSchedules the task to start on or before a specified date. Use this constraint to ensure that a task does not start after a specified date.
Finish No Earlier ThanFNETSchedules the task to finish on or after a specified date. Use this constraint to ensure that a task does not finish before a particular date.
Finish No Later ThanFNLTSchedules the task to finish on or before a specified date. Use this constraint to ensure that a task does not finish after a particular date.
Must Start OnMSOSchedules the task to start on a specified date.
Must Finish OnMFOSchedules the task to finish on a specified date.

We recommend that you use MSO and MFO only when absolutely required as they cause the schedule to be unnecessarily inflexible.

Setting Task Constraints

Task constraints can be set directly from the constraint columns or from the add/edit task screen.