A reorganization framework of the object-oriented class hierarchy

In recent years there has been renewal of interest in the reorganization and transformation of classes for object-oriented design and programming. Numerous attempts have been made by researchers to find algorithms and heuristics to produce "good" and "reusable" class organizations based on the inheritance hierarchy. However, little attention has been given to the reorganization of the aggregation hierarchy which forms the part-of relationship between classes. We are concerned with the inheritance and aggregation hierarchies, and define the object semi-equivalence relation between the class hierarchies by extending the object-equivalence relation. We also present a minimal set of transformations which forms a foundation for reorganization between class hierarchies based on the object semi-equivalence. This set is proven to be correct, complete, and minimal.