Whether you call it a post-project review, lessons learned, post-implementation evaluation or any other term, looking at what went wrong on a project and working out how to do things differently next time is a key way to improve project success.
Most project managers accept the need to do lessons learned activity. Some even do it. But the sessions are normally at the end of a project when the team is itching to get on to new things. You won't all be working together again for the foreseeable future so it isn't really relevant to understand why Sonia made that decision or what Frank would do next time to avoid that error.
The main problems project managers encounter
- People feel unable to express their true interpretations of the project
- People are unwilling to contribute if their manager is there as they don't want to appear negative
- People mix up the person and the act and feedback gets very picky and personal
- People don't care about what happened: they are focused on the future
- Everyone says the project went like a dream and there is nothing constructive raised about areas to improve
- The area that cannot make it to the meeting is targeted and all the failings are blamed on them.
All these issues are to do with human interaction, which is a major skill for all project managers. A skilled facilitator will be able to head off these issues during (or even before) the meeting. For more on managing the people stuff and the soft skills of project management, have a look at Anthony Mersino's blog, EQ4PM.
Let's say that you can handle the people side of things and are interested in the output. At best, this type of 'what went well, what we could improve' or 'pluses and deltas' meeting only helps the people in the room. The lessons rarely get cascaded on to other projects so while each individual might benefit, the way that organization runs projects will not whole-heartedly improve.
One way to counteract this is to schedule lessons learned sessions more regularly through the project. Make it part of each gate review, or part of the closure before you move to a new phase. Or schedule sessions at significant moments in the year like the end of your fiscal year or just before things slow down for summer. Making reviews more regular enhances the likelihood that the lessons will be learned and implemented. A policy of continuous process improvement will also get your team used to the idea that changing the way things are done is part of the project process.
Part of your role as a project manager should also be to improve the quality of the projects that your company does: it's good professional practice to feedback to the other project managers any key points that you have learned that you think they could benefit from. There are various ways to do this: your regular project managers team meeting, via the PMO or informally through an email to everyone. Some organizations have a lessons learned database and this could also be a mechanism to share stories if one is available to you. There are also other online tools like The Mistake Ban, but be careful not to post anything confidential to your company on an external website, even if you think it will help other project managers.