Refinement Verification of Sequence Diagrams Using CSP

Abstract

During the design of systems, models usually evolve from a conceptual level to a more concrete level that is close to how the implementation should be. In a stepwise development, it is required that lower-level models conform to the properties of higher-level models. In this work, we propose a strategy for verifying the refinement of UML sequence diagrams that uses a formal semantics defined in terms of CSP. In order to allow designers to benefit from this strategy we have implemented it in a modelling tool. Such a tool analyses if a sequence diagram is refined by another, that is, we check if the latter preserves the traces of the former sequence diagram. The main contributions of this paper are: (i) the definition of four different notions of sequence diagrams refinement; (ii) an approach to verify the refinement of sequence diagrams in CSP; and (iii) the development of a tool that allows our refinement notions to be verified without any knowledge of the underlying formal semantics. We illustrate our analysis with a text messaging case study.