Infrastructure Support for Engineering Complex Object-Oriented Systems for Evolution

With conventional object technology, systematic engineering of object-oriented systems for evolution is difficult. At best, one can build applications that are evolvable with respect to a few anticipated variation points. However, unanticipated evolution, which accounts for most changes of long-lived software, is not adequately supported. Therefore, infrastructures that support unanticipated software adaptation (USA) and its run-time variant, unanticipated software system reconfiguration (USSR) are a basic prerequisite for effective software evolution. This paper discusses the limitations of existing object technology and sketches an infrastructure for USA / USSR that extends the Java platform by two generic adaptation techniques: object-based inheritance and transmigration of object identity. The TAILOR infrastructure reduces the costs of developing, maintaining and deploying software due to less down-times and increased reuse of existing software when faced with unanticipated change.