Object-oriented reengineering patterns — an overview

Successful software systems must be prepared to evolve or they will die. Although object-oriented software systems are built to last, over time they degrade as much as any legacy software system. As a consequence, one must invest in reengineering efforts to keep further development costs down. Even though software systems and their business contexts may differ in countless ways, the techniques one uses to understand, analyze and transform these systems tend to be very similar. As a consequence, one may identify various reengineering patterns that capture best practice in reverse- and re-engineering object-oriented legacy systems. We present a brief outline of a large collection of these patterns that have been mined over several years of experience with object-oriented legacy systems, and we indicate how some of these patterns can be supported by appropriate tools.