Web Services workflow reliability estimation through reliability patterns

Web Services are one of the most promising technologies for the development of component based systems. Nevertheless, there are still several open issues which limit their potential benefits and impair their adoption. Among these, lack of effective techniques for systems dependability forecasting is a key problem. The approaches proposed in the literature are mainly borrowed from traditional software reliability theory, and they typically do not take into account specific characteristics of the Web Services technology. In this paper, we propose a novel approach to reliability evaluation of a web services based system. The approach exploits the concept of reliability patterns to derive an aggregate reliability function for a wide class of workflow processes. A new technique is also used to determine the reliability of individual services.