On Relationships Between Stochastic Process Algebras with Æmilia and Queueing Network Models

Various models and methods have been proposed and applied for quantitative system performance evaluation, including Queueing Networks (QN) and Stochastic extensions of Process Algebras (SPA), that show different characteristics and advantages. These formalisms have been applied to model and analyze the performance of hardware and software systems at different levels of abstraction, and more recently at the Software Architectures level. In this paper we investigate some relationships between SPA and QN, and more specifically we compare the SPA specifications based on Æmilia and a class of QN. We propose an approach to translate a QN model into an Æmilia specification in order to take advantage of the model definition based on SPA that allows the combination of functional and performance analysis and compositional, graphical and hierarchical modeling of complex systems. This work extends and reverses a previous comparison of the two formalisms based on the mapping from Æmilia specifications to QN. The integration of these two formalisms aims to combine their main advantages as tools for system performance analysis, in order to efficiently describe and analyze both functional and performance properties of system specifications within the same integrated framework.