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.

Orientadores: Eleri Cardozo, Eliane Gomes Guimarães / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-08T01:18:40Z (GMT). No. of bitstreams: 1 Coelho_PauloRodolfodaSilvaLeite_M.pdf: 3632525 bytes, checksum: 73b0d774d1efd6416d8fb34cc8abd4d7 (MD5) Previous issue date: 2006 / Resumo: Este trabalho apresenta uma arquitetura para a construção de laboratórios de acesso remoto (conhecidos como WebLabs). A arquitetura segue o paradigma de computação orientada a serviço (COS). Nesta abordagem cada recurso físico ou lógico do laboratório é modelado como um Serviço Web. Desta forma, os experimentos podem ser disponibilizados pela composição destes serviços. Um modelo conceitual para WebLabs, bem como a implementação deste modelo são apresentados. Experimentos em robótica móvel também foram desenvolvidos como exemplos de utilização deste laboratório / Abstract: This work presents an architeture for building remote access laboratories (also known as WebLabs). The architecture follows the service oriented computing (SOC). In this approach each logical or physical resource of the laboratory is modeled as a Web Service. In this way, the experiments are built through the composition of such services. A conceptual model of WebLabs, as well as an implementation of this model are presented. Experiments in mobile robotic were also developed for this laboratory / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

No description available.

This Master’s Thesis examines and documents challenges related to the flexible interchange of web services within a cross-cloud Service Oriented Computing scenario (SOC).Starting with a theoretical approach, hypotheses are defined and processed to create testing scenarios for a practical examination. Both examinations are used to identify possible challenges. Next, encountered challenges are described, discussed and classified. Lastly, solution approaches to identified challenges are presented. The solution approaches concern related topics, such as service standardization, semantic methods, heuristics, and security/trust mechanisms. Several approaches to different challenges are reviewed in this particular context, to present an overview for future research on the subject.It is remarkable that there will be more service standardization in the future, but to achieve full automation it will be, on the long run, necessary to evolve and adopt more sophisticated solution approaches such as semantic methods or heuristics.This work is embedded into the framework of a research co-operation between the Linnaeus University Växjö and the University of Applied Sciences Karlsruhe. Results however are also applicable to other research scenarios.

Coreografias de serviços Web representam uma forma mais escalável e flexível de compor serviços do que uma abordagem centralizada como a orquestração, e seu papel na integração e comunicação de sistemas de larga escala é vital para os objetivos da SOC (Computação Orientada a Serviços) e da Internet do Futuro. Atualmente coreografias de serviços Web possuem vários desafios de pesquisa, dos quais a qualidade de serviço (QoS) e o monitoramento de coreografias de serviçosWeb são linhas importantes. O objetivo deste trabalho é propor e implementar um mecanismo de monitoramento não intrusivo de coreografias de serviços Web baseado em SLAs (Acordos de Nível de Serviço) que especificam as restrições de atributos de QoS de maneira probabilística. Esta dissertação propõe um mecanismo para coreografias de serviços Web que: (1) define requisitos de QoS; (2) especifica contratos probabilísticos sobre parâmetros de QoS usando SLA; e (3) realiza um monitoramento não intrusivo de coreografias de serviços Web para detectar violações de SLA. / Web services choreographies are a more scalable and flexible way to compose services than a centralized approach like orchestrations, and its role in the integration and communication of large-scale systems is vital for the goals of SoC (Service Oriented Computing) and Future Internet. Currently,Web services choreographies have several research challenges. From all challenges, quality of service (QoS) and monitoring of Web services choreography are important research lines. The goal of this work is to propose and implement a mechanism for non-intrusive monitoring of Web services choreography based on SLAs (Service Level Agreements) that define constraints of QoS attributes in a probabilistic way. This thesis proposes a mechanism for Web services choreographies that:(1) defines QoS requirements; (2) specifies probabilistic contracts on QoS parameters using SLAs; and (3) monitors, non-intrusively, the enactment of Web services choreographies to detect SLA violations.

L'objet de cette thèse est la modélisation de l'échange dynamique de services. La notion de service joue désormais un rôle clé dans le développement, la diffusion et l'implémentation des systèmes distribués. Cette thèse propose une réflexion sur la notion de service et introduit le concept de Génération Dynamique de Service (GDS) comme une approche différente de l'échange de service en informatique, dans laquelle des services sont dynamiquement construits, fournis et utilisés par des agents (humains ou artificiels). Ces échanges de services sont basés sur des conversations qui ont lieu au sein de différentes communautés. Deux caractéristiques de la GDS sont particulièrement mises en avant : l'aspect orienté agent et l'aspect orienté Grid. La thèse se situe donc à l'intersection de trois domaines~: le Service-Oriented Computing (SOC), les Systèmes Multi-Agents (SMA) et GRID. Les trois contributions majeures sont :: (i) la proposition d'un nouveau modèle de représentation et de communication agent, appelé STROBE, qui permet aux agents de développer dynamiquement un langage différent pour chacun de leurs interlocuteurs. Ils sont capables d'interpréter des messages et d'exécuter des services dans des contextes de conversation dédiés; (ii) une fonction, appelée i-dialogue, qui modélise les conversations agents à l'aide des principes de la programmation applicative/fonctionnelle (i.e., flots, évaluation paresseuse, procédures de première classe) ; (iii) un modèle d'intégration GRID-SMA qui représente les capacités des agents par des services Grid. Dans ce modèle, un langage formel, appelé Agent-Grid Integration Language (AGIL), décrit sémantiquement et graphiquement les concepts clés de GRID et SMA, leurs relations, ainsi que les règles de leur intégration. AGIL intègre tous les résultats de la thèse en proposant une formalisation des interactions entre agents pour l'échange de services sur le Grid.

Orientador: Eleri Cardozo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T07:45:33Z (GMT). No. of bitstreams: 1 Souza_VictorAlexandreSiqueiraMarquesde_M.pdf: 2295226 bytes, checksum: 9e36093f901c39f33bc909f01e4bd421 (MD5) Previous issue date: 2006 / Resumo: Novos serviços de rede devem ser desenvolvidos e gerenciados de acordo com os requisitos específicos dos clientes. Nesse contexto, provedores de serviço devem criar uma nova forma de projetar serviços de rede com tempo de desenvolvimento próximo a zero e alto nível de customização e evolução. A customização é necessária para criação de serviços que satisfaçam aos requisítos do cliente enquanto evolução é necessária para adaptar o serviço assim que esses requisitos se alterem. Além disso, clientes têm demandado a capacidade de gerenciar o serviço para manter o uso, configuração e evolução sob seu controle. Este trabalho apresenta uma abordagem baseada na arquitetura orientada a serviço para o desenvolvimento de serviços de rede capazes de cumprir os requisitos de rápida instalação, customização e gerenciamento por parte do cliente. Esta abordagem considera os serviços de rede como um conjunto de elementos interativos implementados como serviços web. A lógica do serviço é expressa através da orquestração de serviços web. Dois serviços para o gerenciamento de conexões em redes ópticas são apresentados como estudo de caso / Abstract: New generation network services must be developed and managed according to the customers' specific requírements. In this context, service providers must devise a way to design network services with near zero development time and high degrees of customization and evolution. Customízation is necessary to fit the service according to the customers requirements, while evolutíon is necessary to adapt the service as soon as these requírements change. ln addition, customers are demanding the ability to manage the service in order to keep the usage, configuratíon, and evolution under their control. This paper presents an approach based on Service Oriented Archítecture (SOA) for developing network services able to fulfill the requirements of rapid deployment, customization, and customer-side manageability. The approach considers the network service as a set of interactíng elements implemented as web services. The service logic is expressed in terms of web services orchestration. Two services for the management of connections in optical networks are presented as a case study / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

Coreografias de serviços Web representam uma forma mais escalável e flexível de compor serviços do que uma abordagem centralizada como a orquestração, e seu papel na integração e comunicação de sistemas de larga escala é vital para os objetivos da SOC (Computação Orientada a Serviços) e da Internet do Futuro. Atualmente coreografias de serviços Web possuem vários desafios de pesquisa, dos quais a qualidade de serviço (QoS) e o monitoramento de coreografias de serviçosWeb são linhas importantes. O objetivo deste trabalho é propor e implementar um mecanismo de monitoramento não intrusivo de coreografias de serviços Web baseado em SLAs (Acordos de Nível de Serviço) que especificam as restrições de atributos de QoS de maneira probabilística. Esta dissertação propõe um mecanismo para coreografias de serviços Web que: (1) define requisitos de QoS; (2) especifica contratos probabilísticos sobre parâmetros de QoS usando SLA; e (3) realiza um monitoramento não intrusivo de coreografias de serviços Web para detectar violações de SLA. / Web services choreographies are a more scalable and flexible way to compose services than a centralized approach like orchestrations, and its role in the integration and communication of large-scale systems is vital for the goals of SoC (Service Oriented Computing) and Future Internet. Currently,Web services choreographies have several research challenges. From all challenges, quality of service (QoS) and monitoring of Web services choreography are important research lines. The goal of this work is to propose and implement a mechanism for non-intrusive monitoring of Web services choreography based on SLAs (Service Level Agreements) that define constraints of QoS attributes in a probabilistic way. This thesis proposes a mechanism for Web services choreographies that:(1) defines QoS requirements; (2) specifies probabilistic contracts on QoS parameters using SLAs; and (3) monitors, non-intrusively, the enactment of Web services choreographies to detect SLA violations.