Specification and Verification of Context-dependent Services

Current approaches for the discovery, specification, and provision of services ignore the relationship between the service contract and the conditions in which the service can guarantee its contract. Moreover, they do not use formal methods for specifying services, contracts, and compositions. Without a formal basis it is not possible to justify through formal verification the correctness conditions for service compositions and the satisfaction of contractual obligations in service provisions. We remedy this situation in this paper. We present a formal definition of services with context-dependent contracts. We define a composition theory of services with context-dependent contracts taking into consideration functional, nonfunctional, legal and contextual information. Finally, we present a formal verification approach that transforms the formal specification of service composition into extended timed automata that can be verified using the model checking tool UPPAAL.Comment: In Proceedings WWV 2011, arXiv:1108.208

Modelling electronic service systems using UML

This paper presents a profile for modelling systems of electronic services using UML. Electronic services encapsulate business services, an organisational unit focused on delivering benefit to a consumer, to enhance communication, coordination and information management. Our profile is based on a formal, workflow-oriented description of electronic services that is abstracted from particular implementation technologies. Resulting models provide the basis for a formal analysis to verify behavioural properties of services. The models can also relate services to management components, including workflow managers and Electronic Service Management Systems (ESMSs), a novel concept drawn from experience of HP Service Composer and DySCo (Dynamic Service Composer), providing the starting point for integration and implementation tasks. Their UML basis and platform-independent nature is consistent with a Model-Driven Architecture (MDA) development strategy, appropriate to the challenge of developing electronic service systems using heterogeneous technology, and incorporating legacy systems

A Formal Semantic Model of the Semantic Web Service Ontology (WSMO)

Semantic Web Services, one of the most significant research areas within the Semantic Web vision, has attracted increasing attention from both the research community and industry. The Web Service Modelling Ontology (WSMO) has recently been proposed as an enabling framework for the total/partial automation of the tasks (e.g., discovery, selection, composition, mediation, execution, monitoring, etc.) involved in both intra- and inter-enterprise integration of Web Services. To support the standardization and tool support of WSMO, a formal semantics of the language is highly desirable. As there are a few variants of WSMO and it is still under development, the semantics of WSMO needs to be formally defined to facilitate easy reuse and future development. In this paper, we present a formal Object-Z semantics of WSMO. Different aspects of the language have been precisely defined within one unified framework. This model not only provides a formal unambiguous model which can be used to develop tools and facilitate future development, but as demonstrated in this paper, can be used to identify and eliminate errors presented in existing documentation

Model Driven Development of m-Health Systems (with a Touch of Formality)

We propose a model driven design and development methodology augmented with formal validation and verification (V&V) for the development of mobile health systems. Systems which deliver healthcare services remotely should be developed using robust and trusted engineering technologies. The methodology instantiates steps in the MDA trajectory using formal methods to verify critical properties of models, to test preservation of those properties in the derived implementations and to effect model transformations by correctness preserving transformations. The methodology is described and some initial modelling is reported

A Formal Model of Semantic Web Service Ontology (WSMO) Execution

Semantic Web Services have been one of the most significant research areas within the Semantic Web vision, and have been recognized as a promising technology that exhibits huge commercial potential. Current Semantic Web Service research focuses on defining models and languages for the semantic markup of all relevant aspects of services, which are accessible through a Web service interface. The Web Service Modelling Ontology (WSMO) is one of the most significant Semantic Web Service framework proposed to date. To support the standardization and tool support of WSMO, a formal semantics of the language is highly desirable. As there are a few variants of WSMO and it is still under development, the semantics of WSMO needs to be formally defined to facilitate easy reuse and future development. In this paper, we present a formal Object-Z semantics of WSMO. Different aspects of the language have been precisely defined within one unified framework. This model provides a formal unambiguous specification, which can be used to develop tools and facilitate future development

Why do people demand health?

This paper proposes several ways to extend the standard model for health and health services. Psychological aspects such as status seeking, identity seeking and health adaptation are modelled within the framework of the Grossman model. While the two first aspects may be important psychological mechanisms, the adaptation process seems to be the most relevant process to model within a theoretical dynamic framework. As far as we know, there are no formal analyses of this process in the economic literature.Grossman; health adaption; health services

The Sensoria Approach Applied to the Finance Case Study

This chapter provides an effective implementation of (part of) the Sensoria approach, specifically modelling and formal analysis of service-oriented software based on mathematically founded techniques. The ‘Finance case study’ is used as a test bed for demonstrating the feasibility and effectiveness of the use of the process calculus COWS and some of its related analysis techniques and tools. In particular, we report the results of an application of a temporal logic and its model checker for expressing and checking functional properties of services and a type system for guaranteeing confidentiality properties of services

Trade in Business Services in General Equilibrium

Trade in business services has been attracting attention from academic researchers, policy makers, and business journalists. While there are many anecdotes, there has been little in the way of formal theory applied to this issue. In this paper, we adapt a general model of fragmentation of production activities to try to capture the specific features of business services. Following a general discussion, we calibrate a numerical general-equilibrium simulation model to a situation in which both trade and foreign investment in services are initially banned to technically infeasible. We then compute three counter-factual scenarios: one in which trade but not investment in services is feasible or allowed, one in which investment but not trade is allowed, and onein which both trade and investment in services are allowed.