Formal Modelling and Verification of Service-Oriented Systems in Probabilistic Event-B

Abstract

Modelling and refinement in Event-B provides a scalable sup- port for the development of complex service-oriented systems. Refinement in Event-B supports a systematic service development by a gradual trans- formation of an abstract specification into a detailed service architecture. In this paper we aim at integrating quantitative assessment of desired quality of essential service attributes into formal modelling process. We propose an approach to creating and verifying a dynamic service architecture in Event- B. Such an architecture can be augmented with stochastic information and transformed into the corresponding continuous-time Markov chain represen- tation. By relying on probabilistic model-checking techniques, we allow for quantitative evaluation of quality of service attributes at early development stages. The approach is illustrated by a simple case study.