Specifying and adapting object behavior during system evolution

Object-oriented software engineering must address new issues during system evolution, namely, the effects of class evolution on existing class methods. A class dictionary graph describes the class structure and relationships of a given domain. A propagation pattern defines object behavior by describing responsibilities among a group of collaborating classes. The behavior described in a propagation pattern is mapped onto the class structure defined in a class dictionary graph, and the appropriate C++ code is generated. Class structures evolve in many ways. The effects of class evolution on the object behavior defined in existing propagation patterns are detailed, and the requirements for adapting propagation patterns during class evolution, as compared to the efforts of maintaining C++ code, are described