The mechanics of completing lessons learned efforts can be deceivingly simple: You get people in a room (physically or otherwise) and discuss opportunities for improvement based on what they experienced during a project. However, many teams and organizations experience difficulty in realizing the full business value they expect from their lessons learned efforts.
First, it is helpful to define what a lesson learned is. In a broad sense, a lesson learned is knowledge created over the course of past work that is recalled and applied to improve present and future efforts. For example, a project team overcoming a challenge by adapting an existing process or tool can yield innovations towards future project approaches.