Task dependencies

A task dependency is created when one task is prevented from starting or finishing based on the state of another task.

The Project application supports several types of dependencies (starting with the Geneva release).

Task time constraints

The Project Task form includes a Time Constraint field, which can be either of these values: Start ASAP or Start on specific date.

  • If the a task is set to Start ASAP: The task appears on the Gantt chart as starting when the dependency allows it. However, a task can start on a later date if a lag value is set for the relationship.
  • If the successor task is set to a Start on Specific Date that is later than the finish date of the predecessor: The successor task starts at the time specified. On the Gantt chart, a lag appears just as if you set the Lag value on the relationship. However, the actual Lag value is not actually modified.
  • If the successor task is set to a Start on Specific Date that is earlier than the finish date of the predecessor: the application changes the successor task time constraint to Start ASAP and the task starts immediately after the predecessor finishes, unless a Lag value exists.
Note: A project property, Retain start on constraint on tasks after adding relations, is available to control the start on time constraint of a successor task. See Project properties for more information.