DOI 10.1007/s00165-004-0044-7 BCS © 2004 Formal Aspects of Computing (2004) 16: 238–262 Formal Aspects of Computing An integrated framework for the performance analysis of asynchronous communicating stochastic processes Natalia L ´ opez, Manuel N ´ u˜ nez and Fernando Rubio Dept. Sistemas Inform´ aticos y Programaci ´ on. Universidad Complutense de Madrid, Spain Abstract. In this paper we present a design framework containing a process algebra and the concurrent functional programming language Eden. In order to study properties of a specification written in our process algebraic nota- tion, we provide a translation mechanism to generate Eden programs. Once we have a translation, we may use the Eden tools to study the performance of the (simulation of the) system. In order to add expressiveness to our design language we use a very powerful process algebra. First, we allow the specification of delays induced by general random variables. We also consider value passing. Finally, the communication between concurrent processes is asynchronous. The usefulness of our framework is presented by two examples featuring all the characteristics of our process algebraic model, we give the corresponding translations, and we provide some performance measures obtained by using Eden tools. Keywords: Stochastic process algebras; Functional programming 1. Introduction It is widely recognized that engineering design languages must be based on a (semi-)formal framework. Actually, in order to build reliable complex systems, it is very important to provide a formal design to contrast the capabili- ties provided by the system and the expected ones. Among the several existing design formalisms, process algebras (see [BPS01] for a good overview of the field) are very suitable to specify concurrent systems because they allow to model them in a compositional manner. First work on process algebras has settled an important theoretical background for the study of concurrent and distributed systems. They were very significant, mainly to shed light on concepts and to open research methodologies. However, due to the abstraction of the complicated features, models were still far from real systems. Therefore, some of the solutions were not specific enough, for instance, those related to real time systems. Thus, researchers in process algebras have tried to bridge the gap between for- mal models described by process algebras and real systems. In particular, features which were abstracted before have been introduced in the models so that they allow the design of systems where not only functional require- ments but also performance ones are included. The most significant of these additions are related to notions of Correspondence and offprint requests to: Natalia L´ opez, Departamento Sistemas Inform´ aticos y Programaci´ on, Facultad de Infom´ atica, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Tel.: +34-91-3947629, Fax: +34-91-3947529, Email:{natalia,mn,fernando} @sip.ucm.es Research supported in part by the Ministerio de Ciencia y Tecnolog´ ı a projects MASTER (TIC2003-07848-C02-01) and AMEVA (TIC2000- 0701-C02-01) and by the Junta de Comunidades de Castilla-La Mancha project PAC-03-001.