[Chris]

Ok, so here's an example. I have a project for the current course I am teaching. I'd like to have a "Prepare for class" subproject that holds all the actions I need to do to prepare for a given class. Here's how the actions might look in that subproject, given the system above:

-> Review notes for today's class.
->-> Edit notes as necessary.
->-> Prepare in-class slides.
->-> Prepare in-class handouts.
->->-> Photocopy handouts.
->-> Prepare homework assignment.
->->-> Photocopy homework assignment.
->-> Make list of demonstration equipment needed.
->->-> Locate demonstration equipment.
->->->-> Setup and test demostrations.

-> Grade papers.
->-> Record grades in roster.

This subproject has two independent actions, reviewing my notes for that day, and grading the papers I'm handing back. Reviewing notes has five children and several grandchildren, while grading papers has only one child (one I often forget until the last minute). Once I review my notes and remind myself what I'm doing in class, I can then proceed to those child actions in any order I want. Of course reviewing notes and its children is independent from grading papers.

I could also have an "After class" subproject, which might have the following actions:

-> Make notes on what worked/didn't work.
->-> Incorporate any needed changes into class notes.
-> Post in-class slides/handouts to Blackboard.
-> Put demonstration equipment away.