Implementing lessons learnt

My main concern with post-implementation reviews, I believe, is the difficulty in sharing the results with others: making sure that others don’t make the same mistakes as you and allowing them to benefit from the things that went well.
What is a post-implementation evaluation?
A meeting to discuss the project’s successes, challenges, and record any lessons for future projects. It is also a way to share corporate knowledge.
A review like this has the following objectives:
To bring everyone together at closing of the project;
To summarize the key lessons learned during the project and to document them in writing
To keep track of this knowledge so that other projects can use it to avoid making the same mistakes as yours or to benefit from what worked well.

Many companies skip the review because it is too short-sighted. The risk there is that best practice for your company is not the same as the professionally-received wisdom about best practice.
You may be able to tell me one way to manage assumptions, but you know your company better than I do. This gives you the opportunity to adapt my advice (or ignore it) and manage assumptions in your organization much better. Learnings from post-implementation reviews are crucial to create a database about how projects work in your organization – literal or figurative.
Two examples of this working well have come to my attention recently. NASA has a huge database of key project lessons, but they are not applicable to most projects in the real world because not many people build rockets. Many of the feedback is technical. However, the US Coast Guard has created a database that has been extremely useful after Hurricane Katrina. They were recently audited and the results can be found in this report: Coast Guard: Observations On the Preparation, Response, and Recover Missions Related To Hurricane Katrina. (GAO-06-903 July 31.
A good sample document is available from Queensland University, Australia (.doc). A second Australian document (.pdf) is also available from the Government Chief Information Office. It’s a comprehensive document (perhaps too detailed to some companies), and the checklist in Appendix C to put together your report is very useful.
* These links were not available when I checked them on 17/4/2011.