To analyze the failure of a process, a group of people answer this question five times: Why did the process fail? The purpose of asking the same question five times is to get to the root cause of the problem. The technique is simple, effective, and engaging.
A facilitator leads the session and makes sure that the responses are connected to the process, not to people. The goal is to keep people from applying we/they during this exercise. Making a mistake in any one answer can lead to misleading results. A facilitator’s responsibility is to guide the team to get to the root cause of a problem that needs to be solved.
Excerpt from: Maximize Performance