This feature is available in Catalyst, Enterprise, and Ultimate editions.
The Story Planner is most helpful during sprint planning, as it allows the team to focus in on one story item or backlog item at a time and fully define its details. Here, you can also add, edit, and prioritize tasks and acceptance tests for the story by dragging and dropping them to the appropriate location.
Select Team > Sprint Planning > Detail Planning.
In the Backlog Items grid, to the right of a story, click Plan Backlog Item.
In the Story Planner window, click Add Task or Add Test from the Add Task drop-down.
Enter the details, and then click Save to return to the Story Planner window.Close the Story Planner window to return to the Detail Planning page.