Project task relationships and dependencies

The Project Management application enables you a create parent-child relationships between tasks and dependencies, such as finish-to-start and finish-to-finish, between tasks.

This table explains the types of task relationships and dependencies that you can create.
Table 1. Project relationships and dependencies
Concept Description
Finish-to-start dependency A dependency that indicates that a task must not be started until its predecessor finishes.
Start-to-start dependency A dependency that indicates that a successor task must not be started until the predecessor task has started.
Start-to-finish dependency A dependency that indicates that a predecessor must not be finished until the successor task starts.
Finish-to-finish dependency A dependency that indicates that a task must not be finished until another task finishes.
Lag time A manually specified time break between predecessor and successor tasks.
Parent task A project task with smaller tasks, referred to as child tasks, underneath it. Child tasks break down the work of a parent task into more manageable subsets. Certain fields for child tasks, such as planned end date, roll up and affect the same field in the parent task.
Child task A project task that is a subset of a larger task. Child task start dates cannot occur before the start date of the parent task.
Rollup task Another term for a parent task in the context of aggregating child task items, such as effort or resources, into a larger parent task calculation. All fields on rollup task forms are read-only.
Roll down State changes roll down from the project to project tasks, and from parent tasks to child tasks.
Note: Only one relationship can exist between two tasks.

The Project Management application provides several properties that control how tasks are calculated and behave. See Project property for more information.