CSOM/PL is a software product line (SPL) derived from applying multi-dimensional separation of concerns (MDSOC) techniques to the domain of high-level language virtual machine (VM) implementations. For CSOM/PL, we modularised CSOM, a Smalltalk VM implemented in C, using VMADL (virtual machine architecture description language). Several features of the original CSOM were encapsulated in VMADL modules and composed in various combinations. In an evaluation of our approach, we show that applying MDSOC and SPL principles to a domain as complex as that of VMs is not only feasible but beneficial, as it improves understandability, maintainability, and configurability of VM implementations without harming performance. / CSOM/PL ist eine Softwareproduktfamilie (software product line, SPL), die erstellt wurde, indem Techniken der mehrdimensionalen Belangtrennung (multi-dimensional separation of concerns, MDSOC) auf die Domäne der virtuellen Maschinen (VM) für höhere Programmiersprachen angewendet wurden. Dazu wurde CSOM, eine in C implementierte Smalltalk-VM, mittels VMADL (virtual machine architecture description language) in Module zerlegt. Etliche Eigenschaften von CSOM wurden in VMADL-Module gekapselt und auf unterschiedliche Weisen komponiert. Die Auswertung des Ansatzes zeigt, dass die Anwendung von MDSOC- und SPL-Prinzipien auf die komplexe VM-Domäne nicht nur machbar ist, sondern darüber hinaus auch Vorteile mit sich bringt, da die Verständlichkeit, Wartbarkeit und Konfigurierbarkeit von VM-Implementierungen ohne Beeinträchtigung der Ausführungsgeschwindigkeit verbessert werden.

Component based software engineering has been perceived to have immense reuse potential. This area has evoked wide interest and has led to considerable investment in research and development efforts. Most of these investigations have explored internal characteristics of software components such as correctness, reliability, modularity, interoperability, understandability, maintainability, readability, portability and generality for promoting reuse. But experience over the past decade and a half has demonstrated that the usefulness of a component depends as much on the context into which it fits as it does on the internal characteristics of the component. Software architecture descriptions that take into account the requirements of the domain can be used to serve as this context. While the Perry, Wolf definition of software architecture has been widely acknowledged, a number of architectural description languages (ADL) have emerged that aim to capture various facets of a software, using varying degrees of formalism. There is currently no agreement towards a standard approach for documenting software architectures which would help define the vocabulary for architectural semantics. In spite of lack of any specification standards for components, Software Product Lines (SPL) and Commercial Off The Shelf (COTS) components do provide a rich supporting base for creating software architectures and promise significant improvements in the quality of software configurations that can be composed from pre-built components. However, further research is needed for evaluation of architectural merits of such component based configurations. In this research, we identify the key aspects of software that need to be specified to enable useful analysis at an architectural level. We also propose a set of metrics that enable objective evaluation of reusability potential. Architectural research has established that software architectural styles provide a way for achieving a desired coherence for component-based architectures. Different architectural styles enforce different quality attributes for a system. Thus, if the architectural style of an emergent system could be predicted, a person playing the role of a system integrator could make necessary changes to ensure that the quality attributes dictated by the system requirements were satisfied before the actual system is built and deployed, thus somewhat mitigating project risks. As part of this research, we propose a model for predicting architectural styles based on use cases that need to be satisfied by a system configuration and demonstrate how our approach can be used to determine stylistic conformance. We also propose objective methods for assessing architectural divergence, erosion and drift during system evolution and maintenance. / text

We present an approach based on Model-Driven Development ideas to create Software Product Lines(SPLs). In Model-Driven SPL approaches, the derivation of a product starts from a domain application model. This model is transformed through several stages reusing model transformation rules until a product is obtained. Transformations rules are selected according to variants included in configurations created by product designers. Configurations include variants from variation points, which are relevant characteristics representing the variability of a product line. Our approach (1) provides mechanisms to improve the expression of variability of Model-Driven SPLs by allowing designers to create fine-grained configurations of products, and (2) integrates a product derivation process which uses decision models and Aspect-Oriented Programming facilitating the reuse, adaptation and composition of model transformation rules. We introduce constraint models which make it possible for product line architects to capture the scope of product lines using the concepts of constraint, cardinality property and structural dependency property. To configure products, we create domain models and binding models, which are sets of bindings between model elements and variants and satisfy the constraint models. We define a decision model as a set of aspects. An aspect maintains information of what and when transformations rules that generate commonalities of products must be intercepted (joinpoints) and what transformation rules (advices) that generate variable structures must be executed instead. Our strategy maintains uncoupled variants from model transformation rules. This solves problems related to modularization, coupling, flexibility and maintainability of transformations rules because they are completely separated from variants; thus, they can evolve independently.

Background: A key idea of feature orientation is to decompose a software product line along the features it provides. Feature decomposition is orthogonal to object-oriented decomposition it crosscuts the underlying package and class structure. It has been argued often that feature decomposition improves system structure (reduced coupling, increased cohesion). However, recent empirical findings suggest that this is not necessarily the case, which is the motivation for our empirical investigation. Aim: In fact, there is little empirical evidence on how the alternative decompositions of feature orientation and object orientation compare to each other in terms of their association with observable properties of system structure (coupling, cohesion). This motivated us to empirically investigate and compare the properties of three decompositions (object-oriented, feature-oriented, and their intersection) of 28 feature-oriented software product lines. Method: In an exploratory, observational study, we quantify internal attributes, such as import coupling and cohesion, to describe and analyze the different decompositions of a feature-oriented product line in a systematic, reproducible, and comparable manner. For this purpose, we use three established software measures (CBU, IUD, EUD) as well as standard distribution statistics (e.g., Gini coefficient). Results: First, feature decomposition is associated with higher levels of structural coupling in a product line than a decomposition into classes. Second, although coupling is concentrated in feature decompositions, there are not necessarily hot-spot features. Third, the cohesion of feature modules is not necessarily higher than class cohesion, whereas feature modules serve more dependencies internally than classes. Fourth, coupling and cohesion measurement show potential for sampling optimization in complex static and dynamic product-line analyses (product-line type checking, feature-interaction detection). Conclusions: Our empirical study raises critical questions about alleged advantages of feature decomposition. At the same time, we demonstrate how the measurement of structural attributes can facilitate static and dynamic analyses of software product lines. (authors' abstract) / Series: Technical Reports / Institute for Information Systems and New Media

Background: A key idea of feature orientation is to decompose a software product line along the features it provides. Feature decomposition is orthogonal to object-oriented decomposition it crosscuts the underlying package and class structure. It has been argued often that feature decomposition improves system structure (reduced coupling, increased cohesion). However, recent empirical findings suggest that this is not necessarily the case, which is the motivation for our empirical investigation. Aim: In fact, there is little empirical evidence on how the alternative decompositions of feature orientation and object orientation compare to each other in terms of their association with observable properties of system structure (coupling, cohesion). This motivated us to empirically investigate and compare the properties of three decompositions (object-oriented, feature-oriented, and their intersection) of 28 feature-oriented software product lines. Method: In an exploratory, observational study, we quantify internal attributes, such as import coupling and cohesion, to describe and analyze the different decompositions of a feature-oriented product line in a systematic, reproducible, and comparable manner. For this purpose, we use three established software measures (CBU, IUD, EUD) as well as standard distribution statistics (e.g., Gini coefficient). Results: First, feature decomposition is associated with higher levels of structural coupling in a product line than a decomposition into classes. Second, although coupling is concentrated in feature decompositions, there are not necessarily hot-spot features. Third, the cohesion of feature modules is not necessarily higher than class cohesion, whereas feature modules serve more dependencies internally than classes. Fourth, coupling and cohesion measurement show potential for sampling optimization in complex static and dynamic product-line analyses (product-line type checking, feature-interaction detection). Conclusions: Our empirical study raises critical questions about alleged advantages of feature decomposition. At the same time, we demonstrate how the measurement of structural attributes can facilitate static and dynamic analyses of software product lines. (authors' abstract) / Series: Technical Reports / Institute for Information Systems and New Media

[pt] A configuração de produto é uma atividade chave para permitir a customização em massa. Ela corresponde a produção de um sistema computacional a partir de uma linha de produtos de software, respeitando as necessidades individuais dos clientes. Na prática, a atividade de configuração do produto pode se tornar uma tarefa complexa, principalmente porque envolve várias partes interessadas com diferentes competências para tomar decisões. Vários trabalhos proprõem decompor a atividade de configuração em estágios pré-estabelecidos, atravrés dos quais os interessados podem tomar suas decisões de forma separada e coerente. No entanto, quando há uma descentralização geográfica do conhecimento necessário em cada etapa e/ou quando os requisitos do cliente forem imprecisos e mudarem com frequência, essas soluções propostas não se aplicam. Para resolver essas questões, este trabalho proprõe uma abordagem de configuração dinâmica e colaborativa de produtos com base na metáfora de assistência pessoal. Os assistentes pessoais num ambiente cooperativo coordenam as decisões dos stakeholders e pró-ativamente executam tarefas, tais como o raciocínio sobre as implicaçõoes das decisões, integrando as decisões distribuídas e resolvendo os requisitos divergentes. Uma ferramenta protótipo, chamada Libertas, e dois cenários ilustrativos que avaliam a aplicabilidade da nossa abordagem também são apresentados. O primeiro cenário analisa o processo de configuração para configurar um sistema operacional para suportar os requisitos de negócio de uma empresa. O segundo aborda um cen´ario com uma linha de produtos de software para portais web. / [en] Product configuration is a key activity for enabling mass customization. It corresponds to tailoring a software application from a software product line, respecting individual customer requirements. In practice, the product configuration activity is challenging, mainly because it involves numerous stakeholders with different expertise making decisions. Several works claim to decompose the configuration activity into pre-arranged stages, whereby stakeholders can make their decisions in a separated way and coherent fashion. However, due to the decentralization in geography of the knowledge required in each stage and that customer requirements could be imprecise and change frequently, the proposed solutions do not apply. To address these issues, this work proposes a dynamic and collaborative product configuration approach based on the personal assistant metaphor. Personal assistants in a cooperative way coordinate stakeholders´ decisions and proactively perform tasks, such as reasoning about the ramifications of decisions, integrating distributed decisions and resolving divergent requirements. A tool prototype, called Libertas, and two case studies that evaluate the applicability of our approach are also presented. The first case study analyzes the configuration process to configure an operational system to support the business requirements of an enterprise. The second one addresses a scenario of a software product line for web portals.

SANTOS, Ismayle de Sousa. Um ambiente para geração de cenários de testes para linhas de produtos de software sensíveis ao contexto. 2013. 135 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências, Departamento de Computação, Fortaleza-CE, 2013. / Submitted by guaracy araujo (guaraa3355@gmail.com) on 2016-07-01T19:23:59Z No. of bitstreams: 1 2013_dis_issantos.pdf: 3899116 bytes, checksum: 671b1907d9f723390441a5b8ed58142c (MD5) / Approved for entry into archive by guaracy araujo (guaraa3355@gmail.com) on 2016-07-01T19:25:01Z (GMT) No. of bitstreams: 1 2013_dis_issantos.pdf: 3899116 bytes, checksum: 671b1907d9f723390441a5b8ed58142c (MD5) / Made available in DSpace on 2016-07-01T19:25:01Z (GMT). No. of bitstreams: 1 2013_dis_issantos.pdf: 3899116 bytes, checksum: 671b1907d9f723390441a5b8ed58142c (MD5) Previous issue date: 2013 / A Context-Aware Software Product Line (CASPL) is a product line for developing context-aware applications, which dynamically change their behavior or provide services based on context information. With this kind of line, the productivity can be increased and the development costs of the context-aware application can be cut down. In this scenario, the testing activity needs to deal with the peculiarities of both context-aware applications and the product line development paradigm. Through the complexity involved in testing a CASPL is essential to have methods or tools for supporting this activity, especially with the goal of creating tests from requirements. The aim of this early testing generation is to identify and fix the defects in the early stages of development. Therefore, this work aims to propose an environment for generating test scenarios for a CASPL that takes into account the presence of context information and seeks to maximize the testing reuse. This environment consists of a testing scenario generation method, a template for textual use case specification and a support tool. The method uses as input textual use cases especifications with information about: funcionality, variability, and how the context afect the final products. The environment also has a use case template that supports the use of the method and a tool support, which allows the modeling of use cases according to this template and implements the proposed method. In order to verify the benefits of the environment as a way to testing generation for a Context-Aware Software Product Line, an assessment in the form of controlled experiment is conducted. Based on the collected results, it is observed that: the use of the template makes easy the understanding of a Context-Aware Software Product Line use case; the method favors the creation of a set of tests with higher coverage than a non-systematic testing generation; and the tool is the necessary support for the method / Uma Linha de Produto de Software Sensível ao Contexto (LPSSC) é uma linha de produto para o desenvolvimento de aplicações sensíveis ao contexto, que alteram dinamicamente o comportamento ou que proveem serviços com base em informações de contexto. Nesse cenário, a atividade de testes precisa lidar ao mesmo tempo com as peculiaridades das aplicações finais, que são sensíveis ao contexto, e com o paradigma de desenvolvimento em linha de produto. Mediante a complexidade envolvida nos testes de uma LPSSC, é fundamental a existência de métodos ou ferramentas de suporte a essa atividade, especialmente com a intenção de criar testes a partir dos requisitos da linha. O objetivo dessa geração precoce dos testes é permitir a identificação e correção dos defeitos nos estágios iniciais de desenvolvimento. Dessa forma, esta dissertação tem por objetivo propor um ambiente de geração de cenários de testes para uma LPSSC que utiliza especificações textuais de casos de uso com informações de contexto e que possibilita a reutilização dos testes. Este ambiente é constituído pela proposta de um método de geração de cenários de testes, de um template para especificação textual de casos de uso de uma LPSSC e de uma ferramenta de apoio. O método utiliza como base especificações textuais de casos de uso com informações sobre: funcionalidade, variabilidade da linha, e como o contexto afeta os produtos finais. O ambiente também contém o template para caso de uso que fornece suporte ao uso do método e a ferramenta de apoio, que permite a modelagem de casos de uso segundo esse template e implementa o método proposto. Com a intenção de verificar os benefícios do ambiente, proposto nesta dissertação, quanto a geração de cenários de testes para uma LPSSC, conduziu-se uma avaliação preliminar na forma de experimento controlado. Baseado nos resultados coletados nessa avaliação percebeu-se que: o template favorece o entendimento de um caso de uso de uma LPSSC; o método favorece a criação de um conjunto de testes com uma maior cobertura para uma LPSSC, se comparado a criação de testes de forma não sistemática; e a ferramenta representa um suporte necessário.

Configuração modelo de features é conhecida por ser uma atividade complexa, demorada e propensa a erros. Esta atividade torna-se ainda mais complicada quando envolve múltiplas partes interessadas no processo de configuração. Trabalhos de pesquisa têm proposto abordagens para ajudar na configuração de modelo de features, mas elas dependem de processos sistemáticos que restringem as decisões de alguns dos stakeholders. Neste trabalho, propomos uma nova abordagem para melhorar o processo de configuração multi-stakeholder, considerando as preferências dos stakeholders expressas através de restrições duras e brandas. Com base em tais preferências, recomendamos diferentes configurações de produto utilizando diferentes estratégias da teoria da escolha social. Nossa abordagem é implementada em uma ferramenta chamada SACRES, que permite criar grupos de stakeholders, especificar preferências dos stakeholders sobre uma configuração e gerar as configurações ideais. Realizamos um estudo empírico para avaliar a eficácia de nossas estratégias no que diz respeito à satisfação individual e justiça entre todos os stakeholders. Os resultados obtidos provem evidência de que estratégias em particular possuem melhor performance em relação à satisfação de grupo, chamadas average e multiplicative considerando as pontuações atribuídas pelos participantes e complexidade computacional. Nossos resultados são relevantes não só no contexto de Linha de Produto de Software, mas também para a Teoria da Escolha Social, dada a instanciação de estratégias de escolha social em um problema prático. / Feature model con guration is known to be a hard, error-prone and timeconsuming activity. This activity gets even more complicated when it involves multiple stakeholders in the con guration process. Research work has proposed approaches to aid multi-stakeholder feature model con guration, but they rely on systematic processes that constraint decisions of some of the stakeholders. In this dissertation, we propose a novel approach to improve the multi-stakeholder con guration process, considering stakeholders' preferences expressed through both hard and soft constraints. Based on such preferences, we recommend di erent product con gurations using di erent strategies from the social choice theory. Our approach is implemented in a tool named SACRES, which allows creation of stakeholder groups, speci cation of stakeholder preferences over a con guration and generation of optimal con guration. We conducted an empirical study to evaluate the e ectiveness of our strategies with respect to individual stakeholder satisfaction and fairness among all stakeholders. The obtained results provide evidence that particular strategies perform best with respect to group satisfaction, namely average and multiplicative, considering the scores given by the participants and computational complexity. Our results are relevant not only in the context software product lines, but also in the context of social choice theory, given the instantiation of social choice strategies in a practical problem.

Made available in DSpace on 2014-12-17T14:56:03Z (GMT). No. of bitstreams: 1 TulioPMC_DISSERT.pdf: 1801045 bytes, checksum: 77adefdeea59e2db6076c8f805d6778f (MD5) Previous issue date: 2012-08-03 / E-learning, which refers to the use of Internet-related technologies to improve knowledge and learning, has emerged as a complementary form of education, bringing advantages such as increased accessibility to information, personalized learning, democratization of education and ease of update, distribution and standardization of the content. In this sense, this paper aims to develop a tool, named ISE-SPL, whose purpose is the automatic generation of E-learning systems for medical education, making use of concepts of Software Product Lines. It consists of an innovative methodology for medical education that aims to assist professors of healthcare in their teaching through the use of educational technologies, all based on computing applied to healthcare (Informatics in Health). The tests performed to validate the ISE-SPL were divided into two stages: the first was made by using a software analysis tool similar to ISE-SPL, called SPLOT and the second was performed through usability questionnaires to healthcare professors who used ISESPL. Both tests showed positive results, proving it to be an efficient tool for generation of E-learning software and useful for professors in healthcare / O e-learning, que se refere ao uso das tecnologias relacionadas ? Internet para aperfei?oar o conhecimento e a aprendizagem, surgiu como uma forma complementar de ensino, trazendo consigo vantagens como o aumento da acessibilidade da informa??o, aprendizado personalizado, democratiza??o do ensino e facilidade de atualiza??o, distribui??o e padroniza??o do conte?do. Neste sentido, o presente trabalho tem como objeto o desenvolvimento de uma ferramenta, intitulada de ISE-SPL, cujo prop?sito ? a gera??o autom?tica de sistemas e-learning para educa??o m?dica, utilizando para isso conceitos de Linha de Produtos de Software. Ela consiste em uma metodologia inovadora para a educa??o m?dica que visa auxiliar o docente da ?rea de sa?de na sua pr?tica pedag?gica por meio do uso de tecnologias educacionais, todas baseadas na computa??o aplicada ? sa?de (Inform?tica em Sa?de). Os testes realizados para validar a ISE-SPL foram divididos em duas etapas: a primeira foi feita atrav?s da utiliza??o de um software de an?lise de ferramentas semelhantes ao ISE-SPL, chamado de SPLOT; e a segunda foi realizada atrav?s da aplica??o de question?rios de usabilidade aos docentes da ?rea da sa?de que utilizaram o ISE-SPL. Ambos os testes demonstraram resultados positivos, comprovando que o ISE-SPL ? uma ferramenta de gera??o de softwares e-learning eficiente e ?til para o docente da ?rea da sa?de

Configuração modelo de features é conhecida por ser uma atividade complexa, demorada e propensa a erros. Esta atividade torna-se ainda mais complicada quando envolve múltiplas partes interessadas no processo de configuração. Trabalhos de pesquisa têm proposto abordagens para ajudar na configuração de modelo de features, mas elas dependem de processos sistemáticos que restringem as decisões de alguns dos stakeholders. Neste trabalho, propomos uma nova abordagem para melhorar o processo de configuração multi-stakeholder, considerando as preferências dos stakeholders expressas através de restrições duras e brandas. Com base em tais preferências, recomendamos diferentes configurações de produto utilizando diferentes estratégias da teoria da escolha social. Nossa abordagem é implementada em uma ferramenta chamada SACRES, que permite criar grupos de stakeholders, especificar preferências dos stakeholders sobre uma configuração e gerar as configurações ideais. Realizamos um estudo empírico para avaliar a eficácia de nossas estratégias no que diz respeito à satisfação individual e justiça entre todos os stakeholders. Os resultados obtidos provem evidência de que estratégias em particular possuem melhor performance em relação à satisfação de grupo, chamadas average e multiplicative considerando as pontuações atribuídas pelos participantes e complexidade computacional. Nossos resultados são relevantes não só no contexto de Linha de Produto de Software, mas também para a Teoria da Escolha Social, dada a instanciação de estratégias de escolha social em um problema prático. / Feature model con guration is known to be a hard, error-prone and timeconsuming activity. This activity gets even more complicated when it involves multiple stakeholders in the con guration process. Research work has proposed approaches to aid multi-stakeholder feature model con guration, but they rely on systematic processes that constraint decisions of some of the stakeholders. In this dissertation, we propose a novel approach to improve the multi-stakeholder con guration process, considering stakeholders' preferences expressed through both hard and soft constraints. Based on such preferences, we recommend di erent product con gurations using di erent strategies from the social choice theory. Our approach is implemented in a tool named SACRES, which allows creation of stakeholder groups, speci cation of stakeholder preferences over a con guration and generation of optimal con guration. We conducted an empirical study to evaluate the e ectiveness of our strategies with respect to individual stakeholder satisfaction and fairness among all stakeholders. The obtained results provide evidence that particular strategies perform best with respect to group satisfaction, namely average and multiplicative, considering the scores given by the participants and computational complexity. Our results are relevant not only in the context software product lines, but also in the context of social choice theory, given the instantiation of social choice strategies in a practical problem.