Abstract
Choosing the right modeling language for developing a system may be a difficult task, which might influence on the cost and quality of the whole subsequent development process. UML and SDL are two of the most widely used modeling languages. The purpose of this paper is to help the modeler decide which of UML and SDL is more appropriate for the particular problem he has to solve, depending on its characteristics. This paper is rooted in a case study, a simplified switching system that we have modeled in SDL-96, UML and SDL-2000. The three models developed in parallel offer a basis for comparing the three languages. The SDL-2000 case study presents an additional interest, since it is one of the first examples of a recently released standard and no example is provided to illustrate it. Based on the parallel case studies we discuss the fitness of SDL-96, UML and SDL-2000 for specific application domains.