I'm a big fan of Creative Problem Solving. It's a facilitated process for tackling non-trivial problems, particularly where there may be a rat's nest of underlying issues that need to be explored.

I often use CPS to help Scrum teams find solutions to tricky problems. My role is as facilitator - it's the team that actually generates the ideas and implementation plan.

I described a CPS case study at the September Agile Tuesday Scrum Stammtisch meeting in Munich. The slides are attached.