You're gaining valuable insight as you work through the process. For any good business man that works on a project it's fairly easy to tear your project to pieces when analyzing what you did wrong. Figuring out want went right is a little harder.
How I would approach a thorough postmortem
Get All Perspectives in Writing
Ask each team member to write a few pages on project observations. Instead of randomly laying a trail for them to fulfill I would ask exact questions that you want to know about. You can supplement this with a meeting, but I rather get someones sole attention without distraction.
The most obvious questions would be
- List your top 5 items you feel went right with the project?
- List your top 5 items you feel went wrong with the project?
I would supplement those questions with specific questions relating to the team and project that you personally want to know from a management position.
- How did you feel about working with Box2D instead of Chipmunk? Would you use (x) again?
- Do you feel the project management was able to do x, y, and z for you?
Fail Early, Fail Often
Well, it is pretty hard to 'fail early' when your project is out of the door. Hopefully the feedback you gain from the above will shed light on processes that may have been pretty dark to you.
There are problems that you will run against that will sting pretty bad. It'll be pretty difficult to just forget those.
To make sure that you don't forget the problem areas it could be handy to write a 'Core Value' type list that you keep at arms reach. Keep them available for others to see and for you to see. When the your next project starts I might be inclined to bring some of these to the table to get other people's perspectives. If you have new eyes on the project you might get feedback that could shed new light on solving a particular issue.
As long as you're aware, and you keep your problems in the light, you're bound to solve those issues.
Grab all of the writings and bring it all together.
- Introduction to the project, goals, and anything you feel like sharing about the project process
- Top 5 - What went right?
- Top 5 - What went wrong?
- Conclusion... Bringing it to the end.