Lessons learned are more useful when they lead to specific changes in future project practices. Exploring the project improvement process provides insight into how teams can capture lessons, analyse recurring problems, and translate findings into actionable improvements. Simply recording lessons does not guarantee that organisational practices will change. Assigning responsibility for implementing and reviewing improvements can make the process more effective. This creates a clearer connection between experience and future performance.
http://www.uniccm.com/continuous-improvement-in-project-management