An analytical approach towards system level performance analysis

System level modeling languages support the creation of executable system models in the earliest stages of the design process. Executable specifications allow the properties of a system to be analyzed and verified before this system is actually being realized in terms of hardware and software components. The POOSL language is a system level modelling language for complex real-time hardware/software systems. The language has proven to be very useful to describe real-life systems and to verify their correctness properties. Unfortunately, currently POOSL does not support the possibility to analyze performance properties. This is a major disadvantage because performance characteristics play a key role in the design of many hardware/software systems. This paper aims at extending the POOSL language with the capabilities to express probabilistic behaviour and to analyze performance figures analytically. The paper complements the work presented in [16] where the focus was on empirical performance analysis. To present the key ideas we develop a real-time probabilistic process calculus that is able to express the basic concepts of POOSL. We introduce an experimental software tool supporting the calculus and it is shown how the tool enables the calculation of the performance of a data link protocol. Keywords— system-level modeling; performance evaluation; formal specification