Des familles de logiciels similaires proviennent fréquemment de pratiques de réutilisation de clones de logiciels existants, qui sont ensuite enrichis ou dépouillés de fonctionnalités pour suivre de nouvelles exigences. Avec le temps, ces variantes se multiplient et se complexifient, et il devient difficile de les maintenir, de les faire évoluer. L’ingénierie des lignes de produits logiciels regroupe un ensemble de méthodes visant à faciliter le développement et la gestion de telles collections de logiciels similaires. Documenter la variabilité est le point central de ce paradigme ; on la représente à travers des modèles de variabilité, qui servent de supports à la grande majorité des processus propres à l’ingénierie des lignes de produits. La migration complète ou partielle de ces familles de logiciels vers des approches de type lignes de produits permet la simplification de leur exploitation. La rétro-ingénierie, la modélisation et la gestion de la variabilité sont reconnues comme une phase cruciale et ardue de cette migration. Par conséquent, de nombreuses approches ont été proposées pour étudier des descriptions de familles de logiciels dans ce but. Plusieurs d’entre elles s’appuient sur l’analyse formelle de concepts, un cadre mathématique de groupement hiérarchique qui organise un ensemble d’objets et leurs descriptions dans une structure canonique mettant naturellement en évidence leurs aspects communs et variables.Dans ce manuscrit, nous défendons l'idée que l’analyse formelle de concepts, plus qu’un outil, offre un véritable cadre structurel et réutilisable à l’étude de la variabilité des familles de produits.Dans un premier temps, nous établissons un panorama des informations sur la variabilité qui sont mises en évidence grâce à ce formalisme, et discutons de son spectre d’applicabilité. Nous étudions les points communs entre les structures conceptuelles produites par l’analyse formelle de concepts et les modèles de variabilité. Dans un second temps, nous illustrons l’utilisation originale de ces structures conceptuelles comme support à des opérations de conception et de recherche d’informations. Enfin, nous élargissons notre champ d’étude aux informations plus complexes définies par des modèles de variabilité qui ont été étendus pour en améliorer l’expressivité, et dont la rétro-ingénierie est encore peu étudiée à ce jour. Nous montrons comment certaines propriétés de l’analyse formelle de concepts permettent de généraliser son utilisation à des descriptions de variantes plus complexes, et étudions son application pour la manipulation d’attributs multivalués et de cardinalités, en complément des caractéristiques booléennes traditionnelles. Nous évaluons notre approche sur des données issues de dépôts tels que SPLOT, fork-insight et de matrices de comparaison de produits de wikipedia. / Software families often rise from reuse practices as cloning existing software products which are then enhanced or pruned to fulfill new requirements. With time, these variants grow in number and in complexity, and become more and more complex to maintain. Software product line engineering gathers a set of methods that aims at facilitating the management and development of such collections of existing variants. Documenting variability is the central point of this paradigm; This variability is represented in variability models that support a large part of software product line engineering processes.The partial or complete migration from software families to a product line approach eases their exploitation.Reverse-engineering, modeling and managing variability are known as crucial tasks of the migration: therefore, numerous methods have been proposed to study descriptions of software families for this goal.Some of them are based on formal concept analysis, a mathematical framework for hierarchical clustering which organises set of objects and their descriptions in canonical structures highlighting naturally their commonalities and variability.In this thesis, we defend that formal concept analysis, more than a tool, is a relevant structural, reusable and extensible framework to study variability of software families.First, we propose an overview of variability information which is highlighted thanks to this framework, and we discuss its scope of applicability.We study the common points between the conceptual structures of formal concept analysis and variability models.Then, we show how to use these conceptual structures to support research and modeling operations.Finally, we broaden the scope of this study to take into account more complex information about extended variability.We evaluate our method on data taken from the SPLOT repository, fork-insight and product comparison matrices from wikipedia.

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.

A popularização dos dispositivos móveis em todas as camadas sociais tem motivado o desenvolvimento de aplicações educacionais móveis, denominadas aplicações de m-learning. Neste cenário, as aplicações existentes, mesmo possuindo diversos benefícios e facilidades no que diz respeito ao ensino e aprendizagem, apresentam problemas e desafios relacionados, sobretudo no que se refere ao desenvolvimento, reuso e padronização arquitetural. Por outro lado, na vertente do reúso de software, percebe-se uma crescente adoção do conceito de Linha de Produtos de Software (LPS). Esse paradigma possibilita às organizações explorar as similaridades e variabilidades de seus produtos, aumentando a reutilização de artefatos e, como consequência, diminuindo custos e tempo de desenvolvimento. Neste trabalho é apresentada uma LPS voltada ao domínio das aplicações de m-learning, denominada M-SPLearning. A proposição da M-SPLearning envolveu desde o estudo inicial para a obtenção de uma análise de domínio efetiva, até a implementação dos componentes previamente analisados. A LPS concebida teve seus respectivos produtos avaliados experimentalmente no cenário industrial, fornecendo evidências de que sua utilização pode acelerar o time-to-market de produtos de m-learning, com um número reduzido de defeitos. / The popularity of mobile devices in all social classes has motivated the development of mobile educational applications, called m-learning applications. The existing applications, even having many benefits and facilities in relation to teaching and learning, also have problems and challenges, especially regarding the development, reuse and architectural standardization. Particularly, there is an increasing adoption of the concept of Software Product Line (SPL) in researches related to reuse. This paradigm enables organizations to explore the similarities and variabilities of their products, increasing the reuse of artifacts and, consequently, reducing costs and development time. This work presents an SPL focused on the domain of m-learning applications, named M-SPLearning. The development of M-SPLearning has comprised since the initial study for an effective domain analysis until the implementation of the components previously analyzed. Such SPL had its products experimentally evaluated in the industrial scenario, providing evidences that its use can accelerate the time-to-market of m-learning applications, with a reduced number of faults.

Over the last decade, software has become an integral part of many products with which it is not traditionally associated (e.g., automobiles, medical equipment, home appliances, etc.). This has led to problems in many organizations, since it has proved difficult to integrate software engineering processes with other engineering processes. To address the increased complexity and to coordinate their engineering efforts, many organizations working in such domains have therefore introduced systems engineering into their business processes. Systems engineering is an interdisciplinary approach to system development. Teamwork is essential in developing complex systems, and systems engineering orchestrates this process throughout the lifespan of a system. The focus of systems engineering is on defining customer needs and required functionality, documenting requirements, synthesizing a design and validating the system. A problem with the traditional techniques of systems engineering is, however, that they provide inadequate support for achieving high levels of reuse between different projects. In this dissertation, methods and tools with the overall purpose of providing an improved reuse infrastructure for systems engineering artifacts and their resulting detailed design artifacts are proposed. The proposed methods and tools are based on the software product-line approach, a reuse strategy which focuses on families of related systems that address particular market segments. Studies have shown that if an empirical study does not report experiences from that which practitioners consider a “real” situation, results are likely to be ignored. Even though case studies cannot achieve the scientific rigor of formal experiments, case studies can provide enough information to decide if a specific technology will benefit a particular organization. To ensure industry-relevant research results, case studies on real development projects were chosen as the main vehicle for performing research. This dissertation reports experiences from four empirical studies which were performed within the Swedish defense industry. The studies indicate that the proposed methods and tools indeed provide an improved reuse infrastructure, compared to the previously used methods and tools.

Variability modeling is one of the key disciplines to cope with complex variability in large software product lines. It aims at creating, evolving, and configuring variability models, which describe the common and variable characteristics, also known as features, of products in a product line. Since the introduction of feature models more than twenty years ago, many variability modeling languages and notations have been proposed both in academia and industry, followed by hundreds of publications on variability modeling techniques that have built upon these theoretical foundations. Surprisingly, there are relatively few empirical studies that aim at understanding the use of such languages. What variability modeling concepts are actually used in practice? Do variability models applied in real-world look similar to those published in literature? In what technical and organizational contexts are variability models applicable? We present an empirical study that addresses this research gap. Our goals are i) to verify existing theoretical research, and ii) to explore real-world variability modeling languages and models expressed in them. We study concepts and semantics of variability modeling languages conceived by practitioners, and the usage of these concepts in real, large-scale models. Our aim is to support variability modeling research by providing empirical data about the use of its core modeling concepts, by identifying and characterizing further concepts that have not been as widely addressed, and by providing realistic assumptions about scale, structure, content, and complexity of real-world variability models. We believe that our findings are of relevance to variability modeling researchers and tool designers, for example, those working on interactive product configurators or feature dependency checkers. Our extracted models provide realistic benchmarks that can be used to evaluate new techniques. Recognizing the recent trend in software engineering to open up software platforms to facilitate inter-organizational reuse of software, we extend our empirical discourse to the emerging field of software ecosystems. As natural successors of successful product lines, ecosystems manage huge variability among and within their software assets, thus, represent a highly interesting class of systems to study variability modeling concepts and mechanisms. Our studied systems comprise eleven highly configurable software systems, two ecosystems with closed platforms, and three ecosystems relying on open platforms. Some of our subjects are among the largest successful systems in existence today. Results from a survey on industrial variability modeling complement these subjects. Our overall results provide empirical evidence that the well-researched concepts of feature modeling are used in practice, but also that more advanced concepts are needed. We observe that assumptions about variability models in the literature do not hold. Our study also reveals that variability models work best in centralized variability management scenarios, and that they are fragile and have to be controlled by a small team. We also identify a particular type of dependencies that is increasingly used in open platforms and helps sustain the growth of ecosystems. Interestingly, while enabling distributed variability, these dependencies rely on a centralized and stable vocabulary. Finally, we formulate new hypotheses and research questions that provide direction for future research.

Nicht-funktionale Eigenschaften geben Aussagen über Qualitätsaspekte einer Software. Mit einer Software-Produktlinie (SPL) wird eine Menge von verwandten Software-Produkten beschrieben, die auf Basis gemeinsam genutzter Bausteine und Architekturen entwickelt werden, um die Anforderungen unterschiedlicher Kundengruppen zu erfüllen. Hierbei werden gezielt Software-Bestandteile wiederverwendet, um Software effizienter zu entwickeln. In dieser Arbeit wird der Einfluss von Eingabedaten auf die nicht-funktionalen Eigenschaften von SPL untersucht. Es wird auf Basis von Messungen ausgewählter nicht-funktionaler Eigenschaften einzelner Software-Produkte ein Vorhersagemodell für beliebige Software-Produkte der SPL erstellt. Das Vorhersagemodell kann genutzt werden, um den Konfigurationsprozess zu unterstützen. Das Verfahren wird anhand einer SPL von verlustfreien Kompressionsalgorithmen evaluiert. Die Berücksichtigung von Eingabedaten kann die Vorhersage von nicht-funktionalen Eigenschaften einer SPL gegenüber einfacheren Vorhersagemodellen ohne die Berücksichtigung von Eingabedaten signifikant verbessern.

Software product lines provide enhanced means for systematic reuse when constructing systems within a particular domain. In order to achieve this, systems in a product line are expected to have a significant amount of commonality. Variability is what distinguishes these systems from one another and is spread across various product line artifacts. This thesis focuses on modeling and managing product line variability. The concept of concerns is proposed as a means of variability modeling. Another proposal is related to the use of context free grammars to represent product line variability and to guarantee that any application derived according to the variability framework thus defined will be a valid one. This approach is evaluated for an example domain, in the light of novel evaluation criteria that are also introduced in the scope of this thesis.

Software product lines provide the opportunity to improve productivity, quality and time-to-market of software-based systems by means of systematic reuse. So as to accomplish systematic software reuse, elicitation of commonality knowledge is to be upheld by the analysis and management of variability knowledge inherent in domain requirements. Considerable effort is devoted to the management of functional variability, often neglecting the impact of quality concerns originating from non-functional requirements. In this thesis, a hybrid approach concentrating on the modeling of quantitative as well as qualitative concerns on quality has been proposed. This approach basically aims to support the domain design process by modeling non-functional variability. It further aims to support application design process by providing trade-off selection ability among quality concerns to control functional features that belong to the same domain. This approach is implemented and evaluated on an example domain to reveal its benefits on non-functional variability.

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