Planning

On the Agile Project Management mailing list, in the midst of an enthusiastic dialogue about the value of planning, Clarke Ching asked the clarifying and orienting question, "What is planning?"

My answer:

plan

1. v. To select assumptions, expectations, constraints, intentions, and commitments to inform decisions about a course of action.
2. n. A description of a set of assumptions, expectations, constraints, intentions, and commitments selected to inform decisions about a course of action.

Before Clarke asked, I didn't know that that's what I meant by planning. That qualifies the question as a good one.

[Update 4:55 PM: Added "intentions."]