You can break tasks into multiple levels of subtasks.
To create a subtask
Note The Parent box in the Task dialog box shows what task the given subtask belongs to.
When you drag a task to another task, the first task becomes a subtask of the second one.
Note To create subtasks by drag'n'drop method, click Manual Sorting on the ribbon, in the Extended group.
When you add subtasks to task, some of its properties become dependent on subtasks.
TipPoint to the task's Due Date to see the details.
Note The latest of subtasks' Due Date is displayed in parentheses.
Note If you add a subtask to a task with time logs and In Progress state, task's time logs are moved to an additional subtask which is created automatically.
If you delete a task that has subtasks, all its subtasks will be deleted.