[en] As the standard for object-oriented analysis and design, the UML (Unified Modeling Language) metamodel, as well as contemporary CASE (Computer-Aided Software Engineering) tools, must provide adequate and integrated support for all essential aspects of software evolution. This includes version control, traceability, impact analysis, change propagation, inconsistency management, and model refactorings. This chapter focuses on the latter two aspects, and shows how tool support for these aspects can be provided. First, we extend the UML metamodel with support for versioning. Second, we make a classification of the possible inconsistencies of UML design models. Finally, we use the formalism of description logics, a decidable fragment of first-order predicate logic, to express logic rules that can detect and resolve these inconsistencies. We also show how the logic rules are used to propose model refactorings. As a proof of concept, we report on the results of initial experiments with a prototype tool we developed for this approach.
