Service Oriented Computing (SOC) provides a framework for the realization of loosely couple service oriented applications (SOA). Web services are central to the concept of SOC. They possess several benefits which are useful to SOA e.g. encapsulation, loose coupling and reusability. Using web services, an application can embed its functionalities within the business process of other applications. This is made possible through web service composition. Web services are composed to provide more complex functions for a service consumer in the form of a value added composite service. Currently, research into how web services can be composed to yield QoS (Quality of Service) optimal composite service has gathered significant attention. However, the number and services has risen thereby increasing the number of possible service combinations and also amplifying the impact of network on composite service performance. QoS-based service composition in the cloud addresses two important sub-problems; Prediction of network performance between web service nodes in the cloud, and QoS-based web service composition. We model the former problem as a prediction problem while the later problem is modelled as an NP-Hard optimization problem due to its complex, constrained and multi-objective nature. This thesis contributed to the prediction problem by presenting a novel learning automata-based non-negative matrix factorization algorithm (LANMF) for estimating end-to-end network latency of a composition in the cloud. LANMF encodes each web service node as an automaton which allows v it to estimate its network coordinate in such a way that prediction error is minimized. Experiments indicate that LANMF is more accurate than current approaches. The thesis also contributed to the QoS-based service composition problem by proposing four evolutionary algorithms; a network-aware genetic algorithm (INSGA), a K-mean based genetic algorithm (KNSGA), a multi-population particle swarm optimization algorithm (NMPSO), and a non-dominated sort fruit fly algorithm (NFOA). The algorithms adopt different evolutionary strategies coupled with LANMF method to search for low latency and QoSoptimal solutions. They also employ a unique constraint handling method used to penalize solutions that violate user specified QoS constraints. Experiments demonstrate the efficiency and scalability of the algorithms in a large scale environment. Also the algorithms outperform other evolutionary algorithms in terms of optimality and calability. In addition, the thesis contributed to QoS-based web service composition in a dynamic environment. This is motivated by the ineffectiveness of the four proposed algorithms in a dynamically hanging QoS environment such as a real world scenario. Hence, we propose a new cellular automata-based genetic algorithm (CellGA) to address the issue. Experimental results show the effectiveness of CellGA in solving QoS-based service composition in dynamic QoS environment.

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Utility Computing is one of the most discussed business models in the context of Cloud Computing. Service providers are more and more pushed into the role of utilities by their customer's expectations. Subsequently, the demand for predictable service availability and pay-per-use pricing models increases. Furthermore, for providers, a new opportunity to optimise resource usage offers arises, resulting from new virtualisation techniques. In this context, the control of service quality and profit depends on a deep understanding of the representation of the relationship between business and technique. This research analyses the relationship between the business model of Utility Computing and Service-oriented Computing architectures hosted in Cloud environments. The relations are clarified in detail for the entire service life cycle and throughout all architectural layers. Based on the elaborated relations, an approach to a delivery framework is evolved, in order to enable the optimisation of the relation attributes, while the service implementation passes through business planning, development, and operations. Related work from academic literature does not cover the collected requirements on service offers in this context. This finding is revealed by a critical review of approaches in the fields of Cloud Computing, Grid Computing, and Application Clusters. The related work is analysed regarding appropriate provision architectures and quality assurance approaches. The main concepts of the delivery framework are evaluated based on a simulation model. To demonstrate the ability of the framework to model complex pay-per-use service cascades in Cloud environments, several experiments have been conducted. First outcomes proof that the contributions of this research undoubtedly enable the optimisation of service quality and profit in Cloud-based Service-oriented Computing architectures.

Linha de Produto de Software (LP) é uma forma sistemática de promover a geração de produtos de software específicos baseados no reúso de uma infraestrutura bem definida. Conceitos de LP aplicados ao domínio de Gestão de Processos de Negócio (BPM - Business Process Management) já apresentaram resultados significativos, entretanto, o escopo de aplicação e os benefícios ainda são limitados. Essas limitações ocorrem, pois as abordagens de LP já existentes para BPM normalmente não cobrem todo o ciclo de vida de processos de negócio e não oferecem o devido tratamento aos aspectos dinâmicos que as organizações demandam para esse domínio. Linha de Produto de Software Dinâmica (LPD) é uma evolução das LPs tradicionais que tem proporcionado uma forma eficiente para lidar com adaptações de produtos em tempo de execução. LPDs podem ser aplicadas, por exemplo, no contexto de arquiteturas SOA (Service-oriented Architecture), que por sua vez podem ser usadas como base tecnológica para viabilizar BPM nas organizações. Dentro desse contexto, este trabalho propõe uma abordagem de LPD para atender as necessidades de organizações interessadas em realizar processos de negócio, por meio de um alinhamento entre conceitos de BPM e SOA. A abordagem proposta aqui, denominada Dynamic Product Line for Business Process Management (DynPL4BPM), visa ser abrangente o suficiente para cobrir todo o ciclo de vida de BPM, sendo previsto o tratamento de aspectos dinâmicos que o domínio de BPM requer. Uma avaliação sistemática e comparativa demonstrou que a abordagem proposta é bem sucedida em apresentar processos bem mais abrangentes que outras soluções similares já propostas na literatura para o mesmo fim. / Software Product Line (PL) is a systematic way to promote the generation of specific software products based on the reuse of a well-defined infrastructure. Concepts of PL applied to Business Process Management (BPM) have already presented significant results; however, the application scope and benefits are still limited. These limitations occur because the existing approaches of LP for BPM usually do not cover the entire lifecycle of business processes and do not provide proper treatment to the dynamic aspects that organizations demand for this domain. Dynamic Software Product Line (DPL) is an evolution of traditional PLs that has provided an efficient way to deal with adaptations of products at runtime. DPLs can be applied, for example, in the SOA (Service-oriented Architecture) context, which in turn can be used as technological basis to enable BPM within organizations. Within this context, this dissertation proposes a DPL approach to meet the needs of organizations interested in carrying out business processes by means of an alignment between BPM and SOA concepts. The approach proposed here, called Dynamic Product Line for Business Process Management (DynPL4BPM), aims to be comprehensive enough to cover the entire BPM lifecycle, including the treatment of dynamic aspects that the BPM domain requires. A systematic and comparative assessment showed that the proposed approach is successful in presenting processes much more comprehensive than other similar solutions already proposed in the literature for the same purpose.

Seleção de serviços em composições distribuídas considera principalmente a qualidade de serviço que atenda requisitos estabelecidos pelo usuário, como por exemplo, preço. No entanto, problemas relacionados a execução de composições de serviços podem ocorrer quando não se considera aspectos relacionados à rede e ao hardware, que afetam diretamente o desempenho da composição. Esse problema se agrava em composições coreografadas, pois a característica descentralizada requer um maior esforço para que essas informações possam ser consideradas em uma perspectiva global. Dessa forma, apesar da descentralização apresentar vantagens, é necessário que requisitos de qualidade de serviço da composição também sejam considerados em coreografias de serviços web para que a escolha de serviços para desempenhar um papel leve em consideração parâmetros importantes que podem afetar no desempenho da composição. Este trabalho apresenta um mecanismo, implementado sobre o framework OpenKnowledge, para selecionar serviços web em ambientes coreografados considerando primeiramente estimativas de atraso, taxa de perda e por fim considera a utilização de outros parâmetros, como utilização de CPU. Os primeiros experimentos em diferentes cenários de rede confirmaram as vantagens da proposta em relação a um seletor de serviços que ignora aspectos relacionados com a rede. Obteve-se ganhos de 20 a 97% no que diz respeito ao tempo total da execução da coreografia. Em seguida, experimentos inserindo utilização de CPU na escolha dos serviços confirmaram as vantagens de utilização de diferentes parâmetros para seleção de serviços em coreografias. / Selection of services in distributed compositions mainly considers the quality of service that meets requirements set by the user, such as price. However, problems related to the execution of service compositions may occur when aspects related to network and hardware, which directly affect the performance of the composition, are not taken in consideration. This problem is aggravated in choreographed compositions because the decentralized feature requires a greater effort so that this information may be considered in a global perspective. Thus, despite the decentralization advantages, it is necessary that the service quality requirements of the composition may also be considered in the choreography of web services so that the choice of services may play a role that takes into account important parameters, which can affect the performance of the composition. This dissertation presents a mechanism, implemented on the OpenKnowledge framework, to select web services in choreographed environments. First, considering delay estimates, loss rate and finally the use of other parameters, such as CPU utilization. The first experiments on different network scenarios confirmed the proposal advantages in relation to a selection mechanism that bypasses aspects of the network. It was obtained gains from 20% to 97% considering the total time of execution of the choreography. Then, experiments inserting CPU utilization in the choice of services confirmed the advantages of using different parameters for selection of services in choreography.

Linha de Produto de Software (LP) é uma forma sistemática de promover a geração de produtos de software específicos baseados no reúso de uma infraestrutura bem definida. Conceitos de LP aplicados ao domínio de Gestão de Processos de Negócio (BPM - Business Process Management) já apresentaram resultados significativos, entretanto, o escopo de aplicação e os benefícios ainda são limitados. Essas limitações ocorrem, pois as abordagens de LP já existentes para BPM normalmente não cobrem todo o ciclo de vida de processos de negócio e não oferecem o devido tratamento aos aspectos dinâmicos que as organizações demandam para esse domínio. Linha de Produto de Software Dinâmica (LPD) é uma evolução das LPs tradicionais que tem proporcionado uma forma eficiente para lidar com adaptações de produtos em tempo de execução. LPDs podem ser aplicadas, por exemplo, no contexto de arquiteturas SOA (Service-oriented Architecture), que por sua vez podem ser usadas como base tecnológica para viabilizar BPM nas organizações. Dentro desse contexto, este trabalho propõe uma abordagem de LPD para atender as necessidades de organizações interessadas em realizar processos de negócio, por meio de um alinhamento entre conceitos de BPM e SOA. A abordagem proposta aqui, denominada Dynamic Product Line for Business Process Management (DynPL4BPM), visa ser abrangente o suficiente para cobrir todo o ciclo de vida de BPM, sendo previsto o tratamento de aspectos dinâmicos que o domínio de BPM requer. Uma avaliação sistemática e comparativa demonstrou que a abordagem proposta é bem sucedida em apresentar processos bem mais abrangentes que outras soluções similares já propostas na literatura para o mesmo fim. / Software Product Line (PL) is a systematic way to promote the generation of specific software products based on the reuse of a well-defined infrastructure. Concepts of PL applied to Business Process Management (BPM) have already presented significant results; however, the application scope and benefits are still limited. These limitations occur because the existing approaches of LP for BPM usually do not cover the entire lifecycle of business processes and do not provide proper treatment to the dynamic aspects that organizations demand for this domain. Dynamic Software Product Line (DPL) is an evolution of traditional PLs that has provided an efficient way to deal with adaptations of products at runtime. DPLs can be applied, for example, in the SOA (Service-oriented Architecture) context, which in turn can be used as technological basis to enable BPM within organizations. Within this context, this dissertation proposes a DPL approach to meet the needs of organizations interested in carrying out business processes by means of an alignment between BPM and SOA concepts. The approach proposed here, called Dynamic Product Line for Business Process Management (DynPL4BPM), aims to be comprehensive enough to cover the entire BPM lifecycle, including the treatment of dynamic aspects that the BPM domain requires. A systematic and comparative assessment showed that the proposed approach is successful in presenting processes much more comprehensive than other similar solutions already proposed in the literature for the same purpose.

Business process analysis and integration are key endeavours for today's enterprises. Recently, Web services have been widely adopted for the implementation and integration of business processes within and across enterprises. In this dissertation, we investigate the problem of enabling the analysis of service interactions, in today's enterprises, in the context of business process executions, and that of service integration. Our study shows that only fraction of interactions in the enterprise are supported by process-aware systems. However, enabling above-mentioned analyses requires: (i) a model of the underlying business process to be used as a reference for the analysis, and (ii) the ability to correlate events generated during service interactions into process instances. We refer to a process model and the corresponding process instances as a "process view". We propose the concept of process space to refer to all process related information sources in the enterprise, over which various process views are defined. We propose the design and development of a system called "process space discovery system" (PSDS) for discovering process views in a process space. We introduce novel approaches for the correlation of events into process instances, focusing on the public processes of Web services (business protocols), and also for the discovery of the business protocol models from the process instances of a process view. Analysis of service integration approaches shows that while standardisation in Web services simplifies the integration in the communication level, at the higher levels of abstractions (e.g., services interfaces and protocol models) services are still open to heterogeneities. We characterise the mismatches between service interfaces and protocol specifications and introduce "mismatch patterns" to represent them. A mismatch pattern also includes an adapter template that aims at the resolution of the captured mismatch. We also propose semi-automated approaches for identifying the mismatches between interface and protocol specifications of two services. The proposed approaches have been implemented in prototype tools, and experimentally validated on synthetic and real-world datasets. The discovered process views, using PSDS, can be used to perform various analyses in an enterprise, and the proposed adaptation approach facilitates the adoption of Web services in business process integration.

Some mechanisms to enable an effective transition from domain models to web service descriptions are developed. The introduced domain modeling support provides verification and correction on the customization part. An automated mapping mechanism from the domain model to web service ontologies is also developed. The proposed approach is based on Feature-Oriented Domain Analysis (FODA), Semantic Web technologies and ebXML Business Process Specification Schema (ebBP). Major contributions of this work are the conceptualizations of a feature model for web services and a novel approach for knowledge-based elicitation of domain-specific outcomes in order to allow designing and deploying services better aligned with dynamically changing business goals, stakeholders&#039 / concerns and end-users&#039 / viewpoints. The main idea behind enabling a knowledge-based approach is to pursue automation and intelligence on reflecting business requirements into service descriptions via model transformations and automated reasoning. The proposed reference variability model encloses the domain-specific knowledge and is formalized by using Web Ontology Language (OWL). Adding formal semantics to feature models allows us to perform automated analysis over them such as the verification of model customizations through exploiting rule-based automated reasoners. This research was motivated due to the needs for achieving productivity gains, maintainability and better alignment of business requirements with technical capabilities in engineering service-oriented applications and systems.

Business process analysis and integration are key endeavours for today's enterprises. Recently, Web services have been widely adopted for the implementation and integration of business processes within and across enterprises. In this dissertation, we investigate the problem of enabling the analysis of service interactions, in today's enterprises, in the context of business process executions, and that of service integration. Our study shows that only fraction of interactions in the enterprise are supported by process-aware systems. However, enabling above-mentioned analyses requires: (i) a model of the underlying business process to be used as a reference for the analysis, and (ii) the ability to correlate events generated during service interactions into process instances. We refer to a process model and the corresponding process instances as a "process view". We propose the concept of process space to refer to all process related information sources in the enterprise, over which various process views are defined. We propose the design and development of a system called "process space discovery system" (PSDS) for discovering process views in a process space. We introduce novel approaches for the correlation of events into process instances, focusing on the public processes of Web services (business protocols), and also for the discovery of the business protocol models from the process instances of a process view. Analysis of service integration approaches shows that while standardisation in Web services simplifies the integration in the communication level, at the higher levels of abstractions (e.g., services interfaces and protocol models) services are still open to heterogeneities. We characterise the mismatches between service interfaces and protocol specifications and introduce "mismatch patterns" to represent them. A mismatch pattern also includes an adapter template that aims at the resolution of the captured mismatch. We also propose semi-automated approaches for identifying the mismatches between interface and protocol specifications of two services. The proposed approaches have been implemented in prototype tools, and experimentally validated on synthetic and real-world datasets. The discovered process views, using PSDS, can be used to perform various analyses in an enterprise, and the proposed adaptation approach facilitates the adoption of Web services in business process integration.

The success of Web services comes from the benefits that it brings in reducing the cost and the time needed to develop data and applications by reusing them, and simplifying their integrations through standardization. However, standardization in Web services does not remove the need for adapters due to possible heterogeneity among service interface and protocol definitions. Moreover, the current service APIs are targeted toward professional programmers, but not accessible to a wider class of users without programming expertise, but would never the less like to build their own integrated applications. In this dissertation, we propose methods and tools to support both service developers and non-expert users in their data and application integration tasks. To support service developers, we propose a framework that enables rapid development of Web service adapters. We investigate particularly the problem of service adaptation focusing on business interface and protocol layers. Our study shows that many differences between business interfaces and protocols are recurring. We introduce mismatch patterns to capture these recurring differences and provide solutions to resolve them. We present the notion of adaptation aspects, which is based on the aspect-oriented programming paradigm, to enable rapid development and deployment of service adapters. We also present a comparative study between standalone and aspect-oriented adapters development. The study shows that the aspect-oriented approach is preferable in many cases, especially when adapters need to access internal states of services. The proposed approach is implemented in a prototype tool, which is used to illustrate how it simplifies adapters development through a case study. To support users without programming expertise, we propose a spreadsheet-based Web mashups development framework, which enables users to develop mashups in the popular spreadsheet environment. First, we provide a mechanism that makes structured data first class values of spreadsheet cells. Second, we propose a new component model that can be used to develop fairly sophisticated mashups, involving joining data sources and keeping spreadsheet data up to date. Third, to simplify mashup development, we provide a collection of spreadsheet-based mashup patterns that captures common Web data access and spreadsheet presentation functionalities. Users can reuse and customize these patterns to build spreadsheet-based Web mashups instead of developing them from scratch. Fourth, we enable users to manipulate structured data presented on spreadsheet in a drag-and-drop fashion. Finally, we have developed and tested a prototype tool to demonstrate the utility of the proposed framework.