Post-Development Software Architecture

Abstract Software architecture (SA) plays an important role in software development. Since the lifecycle stages post development become more and more important and face with many challenges similar to the development, it is a natural idea to introduce or extend SA into the stages post development. In this paper, we present our practices and experiences on applying software architecture into the deployment and maintenance of J2EE (Java 2 Platform Enterprise Edition) applications, including the tool and principles of SAbased J2EE deployment and SA-based J2EE online maintenance. It demonstrates that 1) SA can help to achieve a holistic, finegrained and automated deployment of large-scale distributed systems by visualizing the structure of the system to be deployed; 2) SA can provide an understandable, operational and global view for online maintenance by organizing the fragmented and trivial management mechanisms; 3) Extending SA into the stages post development makes it possible that the whole lifecycle of a software system can be governed by SA with many benefits, e.g. consistency, traceability, responsiveness, etc

CDOXplorer: Simulation-based genetic optimization of software deployment and reconfiguration in the cloud

Migrating existing enterprise software to cloud platforms involves the comparison of various cloud deployment options (CDOs). A CDO comprises a combination of a specific cloud environment, deployment architecture, and runtime reconfiguration rules for dynamic resource scaling. Our simulator CDOSim can evaluate CDOs, e.g., regarding response times and costs. However, the design space to be searched for well-suited solutions is very large. In this paper, we approach this optimization problem with the novel genetic algorithm CDOXplorer. It uses techniques of the search-based software engineering field and simulations with CDOSim to assess the fitness of CDOs. An experimental evaluation that employs, among others, the cloud environments Amazon EC2 and Microsoft Windows Azure, shows that CDOXplorer can find solutions that surpass those of other state-of-the-art techniques by up to 60\%. Our experiment code and data and an implementation of CDOXplorer are available as open source software

An OMG model-based approach for aligning information systems requirements and architectures with business

Tese de Doutoramento (Programa Doutoral em Tecnologias e Sistemas de Informação)The challenges involved in developing information systems (which are able to adapt to rapidly changing business and technological conditions) are directly related to the importance of their alignment with the business counterpart. These challenges comprise issues that cross management and information systems domains, relating and aligning them in order to attain superior performance for the organization, while identifying its strategy and tailoring its business processes. As this relation is increasingly intertwined its concepts are conducted to pragmatic methods, incorporating both management and information systems components, for how, when and where this alignment really matters. The related topics of the alignment between business and information systems comprise diverse paths of research, though with little common ground established inside the community, where problems arouse due to the fast moving business and technological environments. According to these circumstances, the process of developing information systems to support the alignment benefits from incorporating the use of structured and model-based approaches. So, as the development of evermore complex information systems presents a challenge for the currently available methods, the use of models to support the alignment with business stands as an increasingly important issue. Following those challenges, we set out to question how to develop solutions aligning information systems with business in a model-based approach. Accordingly, we support our research on the need to understand what are the perspectives involved in aligning information systems with business, and, moreover, to comprehend in what sense model adoption drives information systems development. So, the proposed goals for this thesis are: (1) set the basis for the elicitation of business requirements in order to support a well-grounded development of information systems; (2) provide for the generation of business models based on the business requirements, while assuring their alignment and traceability; and (3) arrange for the derivation of information system architectures from the business requirements, while attaining alignment and traceability for their mutual transformation and adaptation. Several issues surrounding these goals have already been described and approached in diverse ways by other researchers, where existing approaches and associated methods achieved good results. Nevertheless, these approaches are not without their shortfalls, sometimes failing to present a complete solution, others being unable to adapt to new challenges, or even incapable of reacting to recent trends. In order to tackle these issues we propose to build upon those approaches by adapting, evolving and innovating on solutions in each of the three proposed goals, respectively intertwining with perspectives from related standards and reference models. Answering the first goal, in what regards the main contributions of this thesis, we propose to broaden the elicitation of requirements by relating functional and nonfunctional requirements from business processes. So, we present a unified metamodel representation for those requirements, accompanied by a customizable method for their joint elicitation, based-on business-driven use-cases, goals and rules. This approach adopts the Rational Unified Process (RUP) development methodology and the Business Motivation Model (BMM) standard model language representation for business requirements. Moreover, the metamodel representation and method operationalization are accompanied by a prototype support tool that completes this first contribution. For the second goal, a more business-oriented one correlated to the higher-level requirements, we propose to generate business models directly from the inferred functional and nonfunctional requirements. So, we present a three-dimensional approach built on the relation of the referred requirements with the Balanced Scorecard (BSC) reference model, where an additional mapping to the Business Model Canvas (BMC) is also made available. This proposal provides an associated metamodel representation for the relation between the elements involved and a customizable method for their operationalization, all accompanied by a prototype support tool. On the third goal, focused on system architectures and connected to the lower-level requirements, we propose to derive service-oriented participants from the functional requirements, while aligning the nonfunctional requirements with the quality characteristics of the solution to-be. First, we present an evolution of an existing method for the derivation of a logical architecture, in order to adapt it to a service-oriented approach (SOA). Then, following on the existing relation between the nonfunctional and functional side of the low-level requirements, our approach is able to associate these last with its related services on the derived architecture, in another three-dimensional approach. Additionally, a mapping of the nonfunctional requirements with the system quality characteristics (CISQ) is made available. Once more, an associated metamodel, a customizable method and a prototype support tool are also provided. The development of these three approaches is supported through the execution of tasks which originate artifacts and lead to publications associated to their respective research and development efforts, all according to the Design Science Research (DSR) methodology. These are applied in ongoing projects involving experimental scenarios in industrial settings and associated to established research reference patterns, balancing the interests of both researchers and practitioners while focused both on technology and management audiences. The results obtained from their evaluation reflect the quality and depth of our findings, helping to validate the scientific contribution of this work.Os desafios implicados no desenvolvimento de sistemas de informação (que sejam capazes de se adaptar a condições tecnológicas e de negócios em rápida mutação) estão diretamente relacionados à importância do seu alinhamento com a contraparte do negócio. Esses desafios envolvem questões que cruzam os domínios da gestão e dos sistemas de informação, relacionando-os e alinhando-os com o intuito de alcançar um desempenho superior para a organização, ao mesmo tempo que identificam a sua estratégia e adequam os seus processos de negócio. Como esta relação está cada vez mais interligada, os seus conceitos são canalizados para métodos pragmáticos, incorporando ambos os componentes de sistemas de informação e de gestão, para saber como, quando e onde este alinhamento realmente interessa. Os tópicos relacionados com o alinhamento entre negócio e sistemas de informação abrangem diversos caminhos de pesquisa, embora com poucos alicerces em comum estabelecidos dentro da comunidade, onde os problemas surgem devido às rápidas mudanças nos negócios e nos ambientes tecnológicos. De acordo com estas circunstâncias, o processo de desenvolvimento de sistemas de informação para apoiar o alinhamento beneficia de incorporar o uso de abordagens estruturadas e baseadas em modelos. Assim, dado que o desenvolvimento de sistemas de informação cada vez mais complexos apresenta um desafio para os métodos atualmente disponíveis, o uso de modelos para apoiar o alinhamento com o negócio destaca-se como uma questão cada vez mais importante. Em linha com esses desafios, estabelecemos a questão de como desenvolver soluções para alinhar sistemas de informações com o negócio numa abordagem baseada em modelos. Neste sentido, apoiamos a nossa pesquisa na necessidade de compreender quais são as perspetivas envolvidas no alinhamento dos sistemas de informação com o negócio, e, além disso, de compreender em que sentido a adoção de modelos capacita o desenvolvimento desses sistemas. Assim, os objetivos propostos para esta tese são: (1) definir as bases para o levantamento de requisitos de negócio a fim de suportar um desenvolvimento bem fundamentado de sistemas de informação; (2) disponibilizar a geração de modelos de negócio baseados nos requisitos de negócio, garantindo o alinhamento e a rastreabilidade entre ambos; e (3) estruturar a derivação de arquiteturas de sistema de informação a partir dos requisitos de negócio, preservando o alinhamento e rastreabilidade para a sua mútua transformação e adaptação. Várias questões envolvendo estes objetivos foram já descritas e tratadas de diversas maneiras por outros investigadores, tendo as abordagens existentes e os métodos associados alcançado bons resultados. No entanto, essas abordagens têm as suas lacunas, umas vezes falham em apresentar uma solução completa, noutras são ineficientes ao se adaptarem a novos desafios, ou mesmo incapazes de reagir às novas tendências. Para lidar com estas questões, propomo-nos apoiar nessas abordagens, adaptando, evoluindo e inovando em soluções para cada um dos três objetivos propostos, intersetando-as, respetivamente, com perspetivas de modelos de referência e padrões relacionados. Relativamente ao primeiro objetivo, no que concerne aos principais contributos desta tese, propomos alargar o levantamento de requisitos, relacionando os requisitos funcionais e nãofuncionais dos processos de negócios. Assim, apresentamos um meta-modelo para a representação unificada desses requisitos, acompanhado por um método personalizável para o seu levantamento conjunto, baseada em casos-de-uso, metas e regras orientadas a negócio. Esta abordagem adota a metodologia de desenvolvimento do Rational Unified Process (RUP) e a representação padrão do modelo de linguagem do Business Motivation Model (BMM), para os requisitos de negócio. Além disso, a representação meta-modelo e a operacionalização do método são acompanhados por um protótipo de uma ferramenta de suporte que completa esta primeira contribuição. Quanto ao segundo objetivo, mais orientado ao negócio e correlacionado com os requisitos de nível superior, propomos gerar modelos de negócio a partir dos requisitos funcionais e não-funcionais inferidos. Assim, apresentamos uma abordagem tridimensional, construída sobre a relação dos referidos requisitos com o modelo de referência do Balanced Scorecard (BSC), em que um mapeamento adicional para o Business Model Canvas (BMC) é também disponibilizado. Esta proposta inclui um meta-modelo para representação da relação entre os elementos envolvidos e um método personalizável para a sua operacionalização, tudo acompanhado por um protótipo de uma ferramenta de suporte. No terceiro objetivo, focado em arquiteturas de sistema e ligado aos requisitos de nível inferior, propomos derivar participantes orientados-a-serviços desde os requisitos funcionais, alinhando os requisitos não-funcionais com as características de qualidade da solução a obter. Primeiro, apresentamos uma evolução de um método existente para a derivação de uma arquitetura lógica, adaptando-o a uma abordagem-orientada-a-serviços (SOA). Assim, prosseguindo a relação existente entre o lado não-funcional e funcional dos requisitos de baixo nível, a nossa abordagem associa estes últimos com os serviços relacionados na arquitetura derivada, numa outra abordagem tridimensional. Além disso, um mapeamento dos requisitos não-funcionais com as características de qualidade do sistema (CISQ) é disponibilizado. Mais uma vez, um meta-modelo associado, um método personalizável e um protótipo da ferramenta de suporte são disponibilizados. O desenvolvimento destas três abordagens é suportado pela execução de tarefas, as quais dão origem a artefatos e levam a publicações associadas aos seus esforços de pesquisa e desenvolvimento respetivamente, tudo de acordo com a metodologia DSR. Estas são aplicadas a projetos em andamento, os quais envolvem cenários experimentais em ambientes industriais e associados a padrões de investigação de referência, equilibrando os interesses de investigadores e profissionais assim como dos diferentes públicos de tecnologia e gestão. Os resultados obtidos na sua avaliação refletem a qualidade e a profundidade dos nossos resultados, ajudando a validar a contribuição científica deste trabalho

LAI Research Overview

LAI research overvie

Proceedings of the First International Workshop on Mashup Personal Learning Environments

Wild, F., Kalz, M., & Palmér, M. (Eds.) (2008). Proceedings of the First International Workshop on Mashup Personal Learning Environments (MUPPLE08). September, 17, 2008, Maastricht, The Netherlands: CEUR Workshop Proceedings, ISSN 1613-0073. Available at http://ceur-ws.org/Vol-388.The work on this publication has been sponsored by the TENCompetence Integrated Project (funded by the European Commission's 6th Framework Programme, priority IST/Technology Enhanced Learning. Contract 027087 [http://www.tencompetence.org]) and partly sponsored by the LTfLL project (funded by the European Commission's 7th Framework Programme, priority ISCT. Contract 212578 [http://www.ltfll-project.org

Dagstuhl News January - December 2008

"Dagstuhl News" is a publication edited especially for the members of the Foundation "Informatikzentrum Schloss Dagstuhl" to thank them for their support. The News give a summary of the scientific work being done in Dagstuhl. Each Dagstuhl Seminar is presented by a small abstract describing the contents and scientific highlights of the seminar as well as the perspectives or challenges of the research topic

Avatars, People, and Virtual Worlds: Foundations for Research in Metaverses

Metaverses are immersive three-dimensional virtual worlds in which people interact as avatars with each other and with software agents, using the metaphor of the real world but without its physical limitations. The ubiquitous availability of high speed Internet access has spurred enormous interest in virtual worlds like Second Life and World of Warcraft, both in terms of user gaming and as a new technological platform for global virtual collaboration. These environments have potential for richer, more engaging collaboration, but their capabilities have yet to be examined in depth. Of particular interest in this paper is the use of metaverses for virtual team collaboration. We develop a conceptual model for research in metaverses that is based on five key constructs: (1) the metaverse itself, (2) people/avatars, (3) metaverse technology capabilities, (4) behaviors, and (5) outcomes. We present an in-depth characterization of metaverse technology capabilities from a socio-technical view that recognizes the potential for variation in emergent interaction and in outcomes. Example propositions and a discussion of key issues and challenges show how the model can be used to further research and practice in virtual teams in the context of these new environments

Developing living information systems through systems tailorability: Deferred systems design

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.An interpretivist investigation of computer-based business information systems was conducted in two commercial companies and two higher education institutes, by using both quantitative questionnaire survey and qualitative interview research methods. The investigation focused on the social and organisational context of information systems development and usage in these organisations. The utility of structured methodologies is now being questioned by some researchers who are calling for alternative approaches, and this investigation draws on that alternative strand of thinking. The collected data primarily reveals that the development and usage of information systems happens in changing organisations, which suggests that the design and usage of information systems must cater for such a changing or dynamic environment. Therefore the data is interpreted using a philosophical outlook encompassing the notion of "living" information systems and Critical Theory, and this philosophical stance regards information technology as liberating human endeavour in organisations. Five sub-concepts and the concept of deferred system's design are derived from the data, which have been formulated to account and cater for change in information systems environments. The concept of deferred system's design encourages the design of information systems which allow for organisational human behaviour, consisting of organisational change, uncertainty, and learning, to be mediated by information technology. A systems design principle called `deferred system's design decisions' is derived to enable designs of tailorable information systems, which may be regarded as one form of living information systems to facilitate such organisational behaviour. An intersubjective theoretical model called the spiral of change model of tailorable information systems is proposed to explain and understand better the changing organisational environment in which information systems must be developed and in which they must function. To inform practice a computer tool is proposed which enables conceptions of " tailorable information systems that employ the principle of deferred system's design decisions and enables modelling changing or dynamic information systems