Mel (BOT International, Orlando, Florida, USA) Bost 
Project Management Lessons Learned [PDF ebook] 
A Continuous Process Improvement Framework

Lessons Learned is an important phase in project management. This is when organizations can pave the way for future project success by documenting mistakes so they are not repeated and recording best practices so they are repeated. This book covers the important role a project management office (PMO) plays in promoting lessons learned. Project managers learn how to improve processes by applying lessons learned. The book emphasizes 'actionability, ’ or producing a process improvement that can be acted upon by anyone in the PMO or project team.