5.5 Breaking tasks down into subtasks

It is often advisable to break down large tasks into smaller, manageable subtasks. You can do this by creating an outline tree below a TODO item, with detailed subtasks on the tree¹. To keep the overview over the fraction of subtasks that are already completed, insert either `[/]' or `[%]' anywhere in the headline. These cookies will be updates each time the todo status of a child changes. For example:

     * Organize Party [33%]
     ** TODO Call people [1/2]
     *** TODO Peter
     *** DONE Sarah
     ** TODO Buy food
     ** DONE Talk to neighbor

If you would like a TODO entry to automatically change to DONE when all chilrden are done, you can use the following setup:

     (defun org-summary-todo (n-done n-not-done)
       "Switch entry to DONE when all subentries are done, to TODO otherwise."
       (let (org-log-done org-log-states)   ; turn off logging
         (org-todo (if (= n-not-done 0) "DONE" "TODO"))))
     
     (add-hook 'org-after-todo-statistics-hook 'org-summary-todo)

Another possibility is the use of checkboxes to identify (a hierarchy of) a large number of subtasks (see Checkboxes).