Object evolution by model evolution

Claims concerning the maintainability of object oriented software usually refer to encapsulation and inheritance mechanisms. However, if objects are perceived only from the code level, the potential for higher level maintenance operations is missed. Instead, classical maintenance destroys the relationship that once existed between specification and implementation. The authors present an approach supporting object evolution by specification evolution such that for a substantial class of changes, the ensuing changes in the implementation can either be automatically performed or the compliance with the new overall specification can be assured by automatically generated well focused test suits.