1. Define the Problem
2. Establish Focus and Boundaries
3. Identify Options
4. Choose Among Options
5. Implement

At each step, it is instructive to examine who is "responsible" or involved. In an agile team where team empowerment and self-organization are considered critical success factors, the answer to "who?" fore each step should usually be "the team".

There are however, some situations where decisions are outside the realm of a team's empowerment. As well, some decisions are so trivial that it is wasteful to have the whole team involved. In these trivial decisions, usually another person can take responsibility for all the steps of a decision as a service to the team.

Over time, a team and the organization in which a team operates can evolve a set of standards that describe who acts in each step of a decision under what circumstances.

Many thinking tools described by Edward de Bono in his various books (such as Six Thinking Hats, Lateral Thinking : Creativity Step by Step (Perennial Library), Textbook of Wisdom etc.) can be used at various steps in the decision making process.