This paper is about Web services used in distributed, inter-organizational business cooperation (choreography). In this application scenario, we have a multipart functional convention between all the involved Web services (called partners) in order to reach the purpose of the choreography. In such a scenario, two main problems can occur: i) Can we determine whether the resulted composition of partner is conforming or not to the expected behavior, with respect to the initial cooperation schema? ii) Can we determine whether the cooperation is possible by considering the individual partners ’ behaviors? i.e. are the different partners ’ behaviors compatible between them? In this paper, we address the second problem. We propose a method to model partners ’ behaviors and to check the correctness of the choreography (deadlock-free) based on the properties of one partner’s behavior. 1

Currently, Web services give place to active research and this is due both to industrial and theoretical factors. On one hand, Web services are essential as the design model of applications dedicated to the electronic business. On the other hand, this model aims to become one of the major formalisms for the design of distributed and cooperative applications in an open environment (the Internet). In this paper, we will focus on two features of Web services. The first one concerns the interaction problem: given the interaction protocol of a Web service described in BPEL, how to generate the appropriate client? Our approach is based on a formal semantics for BPEL via process algebra and yields an algorithm which decides whether such a client exists and synthetize the description of this client as a (timed) automaton. The second one concerns the design process of a service. We propose a method which proceeds by two successive refinements: first the service is described via UML, then refined in a BPEL model and finally enlarged with JAVA code using JCSWL, a new language that we introduce here. Our solutions are integrated in a service development framework that will be presented in a synthetic way. KEYWORDS: BPEL, Formal Semantics, Interoperability, Program Synthesis,Language Expressivity

Abstract. Creating new services through composition of existing ones is an attractive option. However, composition can be complex and service compatibility needs to be checked. A rigorous and industrially-usable methodology is therefore desirable required for creating, verifying, implementing and validating composed services. An explanation is given of the approach taken by CRESS (Communication Representation Employing Systematic Specification). Formal verification and validation are performed through automated translation to LOTOS (Language Of Temporal Ordering Specification). Implementation and validation are performed through automated translation to BPEL (Business Process Execution Logic) and WSDL (Web Services Description Language). The approach is illustrated with an application to grid service composition in e-Social Science.

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Service oriented architecture (SOA) is an emergent paradigm that aims at building applications and components by assembling existing ones. Several works on composition aspects have been proposed by researchers and industrial practitioners. The overall observation about these works is that they only provide means for service composition and invocation; but, they offer little support for analysis, and formal checking of composite Web services. In this work, we exploit rewriting logic as a unique semantic formalism for well describing and checking Web services composition. Thanks to this formalization we lean on the category model to give precise and sufficient semantics to Web service behavior. Besides, this high level specification constitutes an executable one, it allows formal analysis using a particular wellfounded language Maude having a proof and prototyping environment.

This thesis presents an approach to design, specify, validate, verify, implement, and evaluate composed web/grid services. Web and grid services can be composed to create new services with complex behaviours. The BPEL (Business Process Execution Language) standard was created to enable the orchestration of web services, but there have also been investigation of its use for grid services. BPEL specifies the implementation of service composition but has no formal semantics; implementations are in practice checked by testing. Formal methods are used in general to define an abstract model of system behaviour that allows simulation and reasoning about properties. The approach can detect and reduce potentially costly errors at design time. CRESS (Communication Representation Employing Systematic Specification) is a domain-independent, graphical, abstract notation, and integrated toolset for developing composite web service. The original version of CRESS had automated support for formal specification in LOTOS (Language Of Temporal Ordering Specification), executing formal validation with MUSTARD (Multiple-Use Scenario Testing and Refusal Description), and implementing in BPEL4WS as the early version of BPEL standard. This thesis work has extended CRESS and its integrated tools to design, specify, validate, verify, implement, and evaluate composed web/grid services. The work has extended the CRESS notation to support a wider range of service compositions, and has applied it to grid services as a new domain. The thesis presents two new tools, CLOVE (CRESS Language-Oriented Verification Environment) and MINT (MUSTARD Interpreter), to respectively support formal verification and implementation testing. New work has also extended CRESS to automate implementation of composed services using the more recent BPEL standard

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