UML for architectural design

Describing the architectural design (i.e. the mapping from a logical functional model to a concrete system) is a general problem in software system engineering. While notations have been defined to describe abstract models and implementations, little work has been done in order to define a notation for architectural design. Solutions are proposed in UML for describing the system software structure and the deployment of software components on a hardware platform. We believe that these UML solutions are not yet mature and that they are incomplete. In our work, we have clarified and extended them in order to model the architectural design. Our starting points are the SISU methodology and the SOON notation, and the architecture design in TIMe. Our work has thus focused on the transition from an SDL specification to a concrete system. However, the solutions that we propose are general and may be applied when using other notations for modelling the abstract system, e.g. UML itself. In this document, we first introduce the architectural design concepts and present the SOON notation. Then we describe the implementation concepts defined in UML and present how these concepts can, together with the UML extension mechanisms, be used for architectural design. We discuss some shortcomings in UML, and also comment on achievements in the Telelogic Tau tools.