It is evident that a single semantics and concrete syntax for the UML will not suffice. The challenge is to restructure the UML in such a way to facilitate graceful evolution and to provide high-level extension mechanisms that facilitate disciplined development of precise modeling languages. A suggested approach is to base UML language extensions on a core set of UML notations, and to use profiles to manage language extensions. Presentations and discussions will focus on identifying the challenges, recognizing limitations, analyzing proposed approaches to refactoring the UML, and creating and using profiles.
