A Formal Approach for the Validation of Web Service Orchestrations

Abstract

A web service composition is considered as a real revolution in SOA (Service Oriented Architecture). It is based on assembling independent and loosely coupled services to build a composed web service. This composition can be described from both a local or a global perspective by respective orchestration or choreography. The validation of web service orchestrations is the main topic of this work. It is based on the verification of two classes of properties: generic and specific properties. The former can be checked for any invoked web services whereas the specific properties are different interdependence relationships between activities within an orchestration process. These properties cannot be directly verified on the orchestration process, so, the authors have to use formal techniques. In this paper, they propose a formal approach for the validation of web service orchestrations. This work adopts WS-BPEL 2.0 as the language to describe the web service orchestration and uses the SPIN model-checker for the verification engine. The WS-BPEL specification is translated into Promela code which is the input language for the SPIN model-checker, in order to check generic and specific properties expressed with LTL (Linear Temporal Logic).