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 successor must not be finished until the predecessor 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.

• Project task dependencies
  A task dependency is created when one task is prevented from starting or finishing based on its relationship with the preceding and succeeding tasks.
• Parent-child task relationships
  If a task is relatively large and requires several users with different skills to manage, break the task into subtasks and create parent-child relationships. A child task is a relatively smaller, manageable size of work.
• Parent-child rollup task calculations
  Date changes, stage changes, and value calculations roll up from child tasks to parent tasks.

Related concepts

• Scheduling conflicts between project tasks
• Change requests and project tasks
• Project task checklists
• Task resources

Related tasks

• Create a project task
• Create a milestone
• Accept or reject project task notifications