Project "Post Mortems" ... What are your experiences?

[Mike]

Project "Post Mortems" (sometimes called "Lessons Learned" discussions) are a great way to improve your own or your organization's project management (PM) skills and results. The idea is that at the end of a project you get everyone together and look back on what happened... the good, the bad, things needing improving, and so on. Typically, this is a structured session (sometimes facilitated by someone outside the project team) that is based on a set of questions that project team members take the time to think about after the project is over and before they conduct the post mortem meeting. (For a typical set of questions and instructions on how to use them, see my online article Project "Post Mortem" Review Questions.)

So what's your experience? Have you found "post mortems" to be valuable? What are the most difficult challenges you face with these sessions? What seems to work really well? Let's talk!