I learned this from my friend Jon Ander Musatadi, a young cooperative entrepreneur from Euskadi.
The Joker asks participants to think about the biggest problem they face in their work and write it on a piece of paper.
Then, in groups, the participants come up with two solutions: the best solution and the worst. The worst solution is like a nightmare scenario.
When the groups are done, the joker instructs them to tear up their best solutions, explaining that the goal is to learn from what we do not want.
The next step is small group discussion of the worst solution -- why is it the worst? What is wrong with it? When all the bad has been brought out and considered, the conversation can shift to how to solve those problems, or how to avoid those errors. It may be that the group reconsiders and finds something of value in the elements of the worst solution.
Share notes and discuss in the whole group.