The diffusion of service oriented architectures introduces the need for novel testing approaches. On the one side, testing must be able to identify failures in the functionality provided by service. On the other side, it needs to identify cases in which the Service Level Agreement (SLA) negotiated between the service provider and the service consumer is not met. This would allow the developer to improve service performances, where needed, and the provider to avoid promising Quality of Service (QoS) levels that cannot be guaranteed.This paper proposes the use of Genetic Algorithms to generate inputs and configurations for service-oriented systems that cause SLA violations. The approach has been implemented in a tool and applied to an audio processing workflow and to a service for chart generation. In both cases, the approach was able to produce test data able to violate some QoS constraints.

Summary. Service Oriented Architectures introduce a major shift of perspective in software engineering: in contrast to components, services are used instead of being physically integrated. This leaves the user with no control over changes that can happen in the service itself. When the service evolves, the user may not be aware of changes, and this can entail unexpected system failures.When a system integrator discovers a service and starts to use it, s/he may need to periodically re-test it to build confidence that i) the service delivers over the time the desired functionality and ii) at the same time it is able to meet Quality of Service requirements. Test cases can be used as a form of contract between a provider and the system integrators: this chapter describes an approach and a tool to allow users to run a test suite against a service to discover if functional and non-functional expectations are maintained over time. IntroductionA challenging issue for the verification and validation of service-oriented systems is the lack of control a system integrator has over the services s/he is using. System integrators select services to be integrated in their systems based on a mixture of functional and non-functional requirements. An underlying assumption is that the service will maintain its functional and non-functional characteristics while being used. However, behind any service there is a software system that undergoes maintenance and evolution activities. These can be due to the addition of new features, the evolution of the existing ones, or to corrective maintenance to cope with problems arisen during the service usage.Whilst the service evolution strategy is out of the system integrators control, any changes to a service may impact on all the systems using it. This is a relevant difference with respect to component-based development: when a component evolves, this does not affect systems that use previous versions of the component itself. Component-based systems physically integrate a copy of the component and, despite the improvements or bug fixing performed in the new component release, systems can continue to use an old version.

Abstract. Web Services are entailing a major shift of perspective in software engineering: software is used and not owned, and operation happens on machines that are out of the user control. This means that the user cannot decide the strategy to migrate to a new version of a service, as it happens with COTS. Therefore, a key issue is to provide users with means to build confidence that a service i) delivers over the time the desired function and ii) at the same time it is able to meet Quality of Service requirements. This paper proposes the use of test cases as a form of contract between the provider and the users of a service, and describes an approach and a tool to allow users running a test suite against a service, to discover if functional or non-functional expectations are maintained over the time. The approach has been evaluated by applying it to two case studies.

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The present paper proposes a structured Product Development Lifecycle (PDL) model to deal with the concept design stage of complex assemblies. The proposed method provides a systematic approach to design, aimed to improve requirements management, project management and communication among stakeholders as well as to avoid project failures reducing project development time. This research also provides suggestions and recommendations for utilizing different analysis, synthesis and assessment methodologies along with the proposed approach. The process developed, named Iterative and Participative Axiomatic Design Process (IPADeP), is consistent with ISO/IEC 15288: 2008 – “Systems and software engineering”, and INCOSE Systems engineering handbook. It is an iterative and incremental design process, participative and requirements driven, based on the theory of Axiomatic Product Development Lifecycle (APDL). IPADeP provides a systematic methodology in which, starting from a set of experts’ assumptions, a number of conceptual solutions are generated, analysed and evaluated. Based on the results obtained, new iterations can be performed for each level of decomposition while product requirements are refined. In this paper, we applied IPADeP to the initial phase of conceptual design activities for DEMO divertor-to-vacuum vessel locking system in order to propose new innovative solutions