As the pace of business change increases, service-oriented (SO) solutions should facilitate easier maintainability as underlying business logic and rules change. To date, little effort has been dedicated to considering how the structural properties of coupling and cohesion may impact on the maintainability of SO software products. Moreover, due to the unique design characteristics of Service-Oriented Computing (SOC), existing Procedural and Object-Oriented (OO) software metrics are not sufficient for the accurate measurement of service-oriented design structures. This thesis makes a contribution to the field of SOC, and Software Engineering in general, by proposing and evaluating a suite of design-level coupling and cohesion metrics for predicting the maintainability of service-oriented software products early in the Software Development LifeCycle (SDLC). The proposed metrics can provide the following benefits: i) facilitate design decisions that could lead to the specification of quality SO designs that can be maintained more easily; ii) identify design problems that can potentially have a negative effect on the maintainability of existing service-oriented design structures; and iii) support more effective control of maintainability in the earlier stages of SDLC. More specifically, the following research was conducted as part of this thesis: - A formal mathematical model covering the structural and behavioural properties of service-oriented system design was specified. - Software metrics were defined in a precise, unambiguous, and formal manner using the above model. - The metrics were theoretically validated and empirically evaluated in order to determine the success of this thesis as follows: a. Theoretical validation was based on the property-based software engineering measurement framework. All the proposed metrics were deemed as theoretically valid. b. Empirical evaluation employed a controlled experimental study involving ten participants who performed a range of maintenance tasks on two SO systems developed (and measured using the proposed metrics) specifically for this study. The majority of the experimental outcomes compared favourably with our expectations and hypotheses. More specifically, the results indicated that most of the proposed metrics can be used to predict the maintainability of service-oriented software products early in the SDLC, thereby providing evidence for the validity and potential usefulness of the derived metrics. Nevertheless, a broader range of industrial scale experiments and analyses are required to fully demonstrate the practical applicability of the metrics. This has been left to future work.

The last decade has attracted lot of research work in service-oriented computing (soc), giving raise to standardized architectures, protocols, and technologies that enable developers to easily expose and reuse services. however, these technologies do not fully consider the users as potential actors in the creation of services based on existing ones, as advocated in web 2.0 paradigm. in this thesis, after a deep investigation of soc and its intrinsic soa paradigm, we propose a new approach based on widgets. we propose the widget-oriented architecture (woa); a new paradigm to enable a user-centric service reuse. in addition, we introduce new innovative mechanisms based on the woa paradigm to overcome current limitations of soa in service composition and business process management fields. this new paradigm, along with the innovative architecture and mechanisms introduced, has been validated through implementation and testing.

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No description available.

SOC, pour Service-Oriented Computing, est un paradigme d’ingénierie qui a attiré beaucoup de travaux de recherche ces dernières années. Ces travaux ont donné lieu à des architectures, protocoles, et standards, afin de permettre à des développeurs d’exposer des services et d’en réutiliser d’autre publiés par des tiers. Cependant, ces technologies sont actuellement limitées aux besoins des développeurs uniquement. L’utilisateur final n’est malheureusement pas considéré comme un acteur potentiel dans le processus de réutilisation de services. Ainsi, contrairement aux principes Web 2.0 qui mettent l’utilisateur final au cœur du processus de génération de contenus et de services, les technologies actuelles de SOC se focalisent plus sur les développeurs. Dans cette thèse, après une étude approfondie de SOC et son paradigme intrinsèque (SOA pour Service-Oriented Architecture), nous proposons un nouveau paradigme basé sur le concept de Widget : WOA (pour Widget-Oriented Architecture). Ce nouveau paradigme vise à permettre la réutilisation de service centrée sur les besoins de chaque utilisateur (user-centric). Basé sur ce nouveau paradigme, nous introduisons de nouveaux mécanismes qui répondent aux limitations des architectures SOA dans les domaines de la composition de services et de la gestion de processus métiers (BPM pour Business Process Management). Ce travail est validé à travers une implémentation et plusieurs démonstrations/expérimentations. / The last decade has attracted lot of research work in service-oriented computing (soc), giving raise to standardized architectures, protocols, and technologies that enable developers to easily expose and reuse services. however, these technologies do not fully consider the users as potential actors in the creation of services based on existing ones, as advocated in web 2.0 paradigm. in this thesis, after a deep investigation of soc and its intrinsic soa paradigm, we propose a new approach based on widgets. we propose the widget-oriented architecture (woa); a new paradigm to enable a user-centric service reuse. in addition, we introduce new innovative mechanisms based on the woa paradigm to overcome current limitations of soa in service composition and business process management fields. this new paradigm, along with the innovative architecture and mechanisms introduced, has been validated through implementation and testing.

Using the Internet for teaching and learning has become a trend in modern higher education, facilitated through the exploitation of advanced computing technologies. Virtual Learning Environment (VLE) applications support online learning over the Internet, and VLEs have thus emerged as e-learning domains that are essential prerequisites in cutting edge design and implementation technologies in education. Service Oriented Computing (SOC), as a novel software development and implementation approach, has become an active area of research and development. Web services, as an example of SOC, support the integration of software applications in an incremental way, using existing platforms and languages that utilize and adopt existing legacy systems. Thus, VLEs should be particularly well suited to Web services through the SOC approach. VLE services is a field subjected to continuous development but VLEs as Web services are still not generally accessible for academic institutions, although they have been adopted by some scientific projects. The next generation of VLEs should address the limitations of the current online systems by providing a richer context for online learning, one that is sensitive to the specific domain requirements of e-learning. Web Services Matching and Selection (WSMS), as a part of the functional requirements of Web services, has received less attention from SOC researchers. It involves discovering a set of semantically equivalent services by filtering a set of available services based on service metadata, and instantaneously selecting the best possible service. WSMS is the discovery of a service by a user, where correspondence is established between the objectives of the consumer and the capabilities of the service. It thereby aims to match and select the optimal service that best meets the requestor's needs. The main aim of this doctoral work is to explore novel architectural designs for VLEs, based on the SOC paradigm and its related techniques. In addition, this investigation aims to extend the core ideas behind VLE tools, which are gradually becoming dominant within academic institutes. Another aim is to devise a policy- based technique to enforce security requirements for VLEs and to build a test-bed for VLE security based on Modular Moodle. The fundamental contribution of this thesis that it demonstrates that VLEs can be considered as services, which can be published, discovered and composed as perceived in the SOC paradigm. An additional contribution to the knowledge is that it has built a new extension to the structure of Web services: the Web Services Matching and Selection (WSMS) system. Another contribution to the knowledge is that traditional security requirements have been modified to cater for the highly mobile and changeable environment of VLEs; this has been achieved through policy- based techniques. These contributions to the body of knowledge have been published in learned journals and at conferences.

O processo de elaboração, execução, coleta e análise de dados de experimentos ambientais com abelhas utilizando meios computacionais como suporte a pesquisa, é uma atividade complexa por exigir do pesquisador conhecimentos específicos aos quais ele não foi preparado para atuar. Laboratórios virtuais conhecidos como Weblabs são ferramentas de apoio a pesquisa, pois permitem a realização de experimentos sem a necessidade da presença física da equipe de pesquisadores. O modelo matemático utilizado junto com a sua interpretação são partes do experimento, porém não são tratados dessa maneira atualmente nos Weblabs. Este trabalho propõe a especificação de uma arquitetura de referência a ser empregada como modelo para permitir o desenvolvimento de componentes que disponibilizem serviços com a capacidade de efetuar a integração de dados coletados por meio de experimentos científicos executados com o auxílio dos Weblabs com ferramentas especialistas voltadas a experimentos ambientais e de biodiversidade. A especificação é baseada no paradigma de arquitetura orientada a serviços, permitindo o gerenciamento de análise de experimentos utilizando Weblabs e disponibilizando os serviços especificados para funcionamento em ambientes distribuídos. Este modelo é a base para um estudo de caso com a elaboração de uma prova de conceito, por meio do desenvolvimento de um componente que publique, disponibilize e integre os dados coletados em um Weblab com uma ferramenta especialista em análises ambientais. / The preparation, execution, collection and closing of an experiment using computational means to support the research, is a complex activity because it requires specific knowledge of the researcher to whom he was not prepared to act. WebLabs are known support tools to researchers, because they allow performing experiments without the physical presence of the research team. Among the activities undertaken by the researcher, after collecting data, performs the analysis of data, in which mathematical and statistical models are applied to interpret the data. In a Weblab experiments are performed through web in remote laboratories, and also needed to analyze the data obtained with the data collection. The mathematical model used along with their interpretation are events that are part of the experiment, but are not treated that way today in Weblabs. This paper proposes the specification of reference architecture to be used as a template to allow the development of components that provide services with the ability to make the integration of data collected through scientific experiments carried out with the help of weblabs with tools aimed at environmental and biodiversity experiments. The specification is based on the paradigm of service oriented architecture, allowing management analysis using Weblab experiments and providing the services specified for operation in distributed environments. This model is the basis for a case study with the development of a proof of concept, through development of a component that publishes and distributes and integrates the data collected in a Weblab with a special tool in environmental analysis.

O processo de elaboração, execução, coleta e análise de dados de experimentos ambientais com abelhas utilizando meios computacionais como suporte a pesquisa, é uma atividade complexa por exigir do pesquisador conhecimentos específicos aos quais ele não foi preparado para atuar. Laboratórios virtuais conhecidos como Weblabs são ferramentas de apoio a pesquisa, pois permitem a realização de experimentos sem a necessidade da presença física da equipe de pesquisadores. O modelo matemático utilizado junto com a sua interpretação são partes do experimento, porém não são tratados dessa maneira atualmente nos Weblabs. Este trabalho propõe a especificação de uma arquitetura de referência a ser empregada como modelo para permitir o desenvolvimento de componentes que disponibilizem serviços com a capacidade de efetuar a integração de dados coletados por meio de experimentos científicos executados com o auxílio dos Weblabs com ferramentas especialistas voltadas a experimentos ambientais e de biodiversidade. A especificação é baseada no paradigma de arquitetura orientada a serviços, permitindo o gerenciamento de análise de experimentos utilizando Weblabs e disponibilizando os serviços especificados para funcionamento em ambientes distribuídos. Este modelo é a base para um estudo de caso com a elaboração de uma prova de conceito, por meio do desenvolvimento de um componente que publique, disponibilize e integre os dados coletados em um Weblab com uma ferramenta especialista em análises ambientais. / The preparation, execution, collection and closing of an experiment using computational means to support the research, is a complex activity because it requires specific knowledge of the researcher to whom he was not prepared to act. WebLabs are known support tools to researchers, because they allow performing experiments without the physical presence of the research team. Among the activities undertaken by the researcher, after collecting data, performs the analysis of data, in which mathematical and statistical models are applied to interpret the data. In a Weblab experiments are performed through web in remote laboratories, and also needed to analyze the data obtained with the data collection. The mathematical model used along with their interpretation are events that are part of the experiment, but are not treated that way today in Weblabs. This paper proposes the specification of reference architecture to be used as a template to allow the development of components that provide services with the ability to make the integration of data collected through scientific experiments carried out with the help of weblabs with tools aimed at environmental and biodiversity experiments. The specification is based on the paradigm of service oriented architecture, allowing management analysis using Weblab experiments and providing the services specified for operation in distributed environments. This model is the basis for a case study with the development of a proof of concept, through development of a component that publishes and distributes and integrates the data collected in a Weblab with a special tool in environmental analysis.

The concepts of processes and services can be used to structure both businesses and software systems. From a business perspective, the use of processes promises efficient management of organizations. From a software perspective, executable process descriptions provide a way to structure software systems according to the business process the systems should support. Furthermore, the concept of software services allows systems to be partitioned in a modular fashion, thereby enabling large-scale system integration on a technical level. By combining process descriptions with software services in service-based processes, it is feasible to address both business and more technical software needs. Aligning the business and software perspectives of processes and software services is, however, challenging, since implemented executable processes and software services need to cater for operational and strategic business needs as well as existing legacy software systems. In this thesis, several instruments are presented that aim at aiding the design and evolution of service-based processes. The aligning of operational business and software perspectives on process descriptions is addressed by the introduction of business and technical process model levels. These levels can be aligned by the use of a set of model transformations and associated transformation rules. Furthermore, the aligning is aided by introducing means for achieving flexibility on both the business and technical model levels. The development of service-based processes from a strategic business point of view is aided by the introduction of novel models and methods for goal-based design of software services. Taken together, the instruments can be used for the design and evolution of service-based processes. / QC 20100810 / REMS / Serviam

Service Oriented Computing(SOC) is becoming a major paradigm for developing next generation of software systems, and one of the major challenges of Service Oriented Computing is testing interactions and collaborations among the distributed and dynamically integrated web services. To support automated test of web service‟s collaborations, a formal specification is needed. This thesis proposes a specification of web services collaborations based on Web Services Choreography Description Language (WS-CDL). We identify the basic constructs that can be found in any web services collaboration, and we mapped them to the new WS-CDL based language (WS-CDL+). Finally, A scenario of web services collaboration is developed and specification in WS-CDL+ is provided. This work builds a foundation for automated web services testing in a service oriented computing environment.