Performance Evaluation of SDL Systems Adjunct by Queueing Models

Designing complex systems requires formal methods supporting validation and performance evaluation before implementation. Here we introduce a method based on the adjunction of queueing stations to SDL-specifications. The resulting integrated model combines functional and non-functional properties, in particular it is assessable by quantitative evaluation techniques. As a consequence SDL-specifications may serve as a basis for performance evaluations of systems during the design phase. Here we present the basic concepts of this approach, propose a syntax for attaching performance submodels to SDL-specifications and sketch a tool that employs our approach. The scope of the proposed method is illustrated by an example from the telecommunication area.