A schedule constraint is a limitation placed on a project schedule that affects the start or end date of an activity. Schedule constraints can take the form of fixed imposed dates for a work item. For example, a constraint date can be used to restrict the start of an activity to occur no earlier than a specified date, rather than allowing the dates to be determined by the planning process.
This feature is available only if you are using the Formal Project Management process template.
- As soon as possible (default)
- Start no earlier than
- Finish no later than
When a constraint date is applied to a work item, that date takes precedence over dependency resolution dates during the scheduling process.
As soon as possible
This is the default constraint type. This constraint schedules the work item to the earliest possible time that the work item can start, based on the existing project schedule. This constraint does not admit a fixed date.
When you create a project release or iteration plan, and assign work items to the plan, all work items in the plan are scheduled to start on the same date as the release or iteration plan start date. If you create new work items and assign them to a plan that is already in progress, then those work items are scheduled to start on the current date.
Start no earlier than
Use this constraint to restrict a work item to start on or after a specified constraint date. When you apply this constraint to a task, you must specify the constraint date before which the task must not start. To apply this constraint, select the constraint type as Start no earlier than, and specify the constraint date as the date on or before which the work item must not start.
Finish no later than
This constraint restricts the work item to complete on or before a specified constraint date. When you apply this constraint to a task, you must specify the constraint date by which the task must complete. To apply this constraint, you must select the constraint type as Finish no later than, and specify the constraint date as the date on or before which the work item must be complete.