Dependability certification of services: a model-based approach

The advances and success of the Service-Oriented Architecture (SOA) paradigm have produced a revolution in ICT, particularly, in the way in which software applications are implemented and distributed. Today, applications are increasingly provisioned and consumed as web services over the Internet, and business processes are implemented by dynamically composing loosely coupled applications provided by different suppliers. In this highly dynamic context, clients (e.g., business owners or users selecting a service) are concerned about the dependability of their services and business processes. In this paper, we define a certification scheme that allows to verify the dependability properties of services and business processes. Our certification scheme relies on discrete-time Markov chains and awards machine-readable dependability certificates to services, whose validity is continuously verified using run-time monitoring. Our solution can be integrated within existing SOAs, to extend the discovery and selection process with dependability requirements and certificates, and to support a dependability-aware service composition.