Reasoning on UML Class Diagrams using Description Logic Based Systems Daniela Berardi, Diego Calvanese, Giuseppe De Giacomo Dipartimento di Informatica e Sistemistica Universit`a di Roma “La Sapienza” Via Salaria 113, 00198 Roma, Italy lastname @dis.uniroma1.it Abstract In this paper we study how automated reasoning systems based on Description Logics (DLs) can be used for reasoning about UML class di- agrams. The ability of reasoning automatically on UML class diagrams makes it possible to provide computer aided support during the appli- cation design phase in order to automatically detect relevant properties, such as inconsistencies and redundancies. We show that UML class dia- grams can be formalized as knowledge bases expressed in the DL DLR. DLR knowledge bases can be translated into knowledge bases expressed in the variants of ALCQI accepted by state-of-the-art DL-based systems. Hence, in principle, the reasoning capabilities of such systems can be used to reason on UML class diagrams. However, we report some experiments indicating that state-of-the-art systems have still difficulty in dealing with the resulting knowledge bases. 1 Introduction The Unified Modeling Language (UML) is the de facto standard formalism for object-oriented modeling [1, 11]. There is a vast consensus on the need for a precise semantics for UML [9, 14], in particular for UML class diagrams. Indeed, several kinds of formalizations of UML class diagrams have been proposed in the literature [8, 9, 10, 7]. Many of them have been proved very useful with respect to the task of establishing a common understanding of the formal meaning of UML constructs. However, to the best of our knowledge, none of them has the explicit goal of building a solid basis for allowing automated reasoning techniques, based on algorithms that are sound and complete wrt the semantics, to be applicable to UML class diagrams. 1