In software engineering, software reuse has been a popular topic since 1968. Nowadays, Software Product Line (SPL) engineering promotes systematic reuse throughout the whole software development process. Within SPL, reusability strongly depends on variability. In this context, variability modelling and management are crucial activities that crosscuts all development stages. Different techniques are used to model variability and one of them is Feature Diagrams (FDs). FD languages are a family of popular modelling languages used to model, and reason on, variability. Since the seminal proposal of a FD language, namely FODA, many extensions have been proposed to improve it. However, the pros and cons of these languages are difficult to evaluate for two main reasons: (1) most of them are informally defined and (2) no well defined criteria were used to justify the extensions made to FODA. As a consequence, variability modelling and management techniques proposed in the literature or used by practitioners may be suboptimal. Globally, this work underlines that the current research on FDs is fragmented and provides principles to remedy this situation. A formal approach is proposed to introduce more rigour in the motivation, definition and comparison of FD languages. Thereby, examining their qualities should be more focused and productive. A formal approach guarantees unambiguity and is a prerequisite to define formal quality criteria and to produce efficient and safe tool automation. A quality analysis is necessary to avoid the proliferation of languages and constructs that are an additional source of misinterpretations and interoperability problems. The creation or selection of a FD language should be driven and motivated by rigourous criteria. Translations from one FD language to another should be defined and carefully studied to avoid interoperability problems. The main contributions of this work are: (1) to use a quality framework to serve as a roadmap to improve the quality of FD languages, (2) to formally evaluate and compare FD language qualities according to well-defined criteria and following a clear method, (3) to formally define and motivate a new FD language that obtains the best scoring according to the quality criteria and (4) to develop tool support for this language.

A software product line is a set of software-intensive systems that share a common, managed set of features satisfying the specificneeds of a particular market segment or mission. The main attractive part of SPL is developing a set of common assets which includes requirements, design, test plans, test cases, reusable software components and other artifacts. Tools for the development of softwareproduct line are very few in number. The purpose of these tools is to support the creation, maintenance and using different versions ofproduct line artifacts. This requires a development environment that supports the management of assets and product development,processes and sharing of assets among different products. The objective of this master thesis is to investigate the available tools which support Software Product Line process and itsdevelopment phases. The work is carried out in two steps, in the first step available Software Product Line tools are explored and a list of tools is prepared, managed and a brief introduction of each tool is presented. The tools are classified into different categoriesaccording to their usage, relation between the tools is established for better organization and understanding. In the second step, two tools Pure::variant and MetaEdit+ are selected and the quality factors such as Usability, Performance, Reliability, MemoryConsumption and Capacity are evaluated.

Mobile applications are developed to run on fast-evolving platforms, such as Android or iOS. Respective mobile devices are heterogeneous concerning hardware (e.g., sensors, displays, communication interfaces) and software, especially operating system functions. Software vendors cope with platform evolution and various hardware configurations by abstracting from these variable assets. However, they cannot be sure about their assumptions on the inner conformance of all device parts and that the application runs reliably on each of them—in consequence, comprehensive testing is required. Thereby, in testing, variability becomes tedious due to the large number of test cases required to validate behavior on all possible device configurations. In this paper, we provide remedy to this problem by combining model-based testing with variability concepts from Software Product Line engineering. For this purpose, we use feature-based test modeling to generate test cases from variable operational models for individual application configurations and versions. Furthermore, we illustrate our concepts using the commercial mobile application “runtastic” as example application.

Software Product Line Engineering (SPLE) has been proven to reduce development and maintenance costs, improving the time-to-market, and increasing the quality of product variants developed from a product family via systematic reuse of its core assets. SPLE has been successfully used in the development of safety-critical systems, especially in automotive and aerospace domains. Safety-critical systems have to be developed according to safety standards, which demands safety analysis, Fault Tree Analysis (FTA), and assurance cases safety engineering artefacts. However, performing safety analysis, FTA, and assurance case construction activities from scratch and manually for each product variant is time-consuming and error-prone, whereas variability in safety engineering artefacts can be automatically managed with the support of variant management techniques. As safety is context-dependent, context and design variation directly impact in the safety properties changing hazards, their causes, the risks posed by these hazards to system safety, risk mitigation measures, and FTA results. Therefore, managing variability in safety artefacts from different levels of abstraction increases the complexity of the variability model, even with the support of variant management techniques. To achieve an effective balance between benefits and complexity in adopting an SPLE approach for safety-critical systems it is necessary to distinguish between reusable safety artefacts, whose variability should be managed, and those that should be generated from the reused safety artefacts. On the other hand, both industry and safety standards have recognized the use of model-based techniques to support safety analysis and assurance cases. Compositional safety analysis, design optimization, and model-based assurance cases are examples of techniques that have been used to support the generation of safety artefacts required to achieve safety certification. This thesis aims to propose a model-based approach that integrates model-based development, compositional safety analysis, and variant management techniques to support the systematic reuse and generation of safety artefacts in safety-critical software product line engineering. The approach contributes to reduce the effort and costs of performing safety analysis and assessment for a particular product variant, since such analysis is performed from the reused safety artefacts. Thus, variant-specific fault trees, Failure Modes and Effects Analysis (FMEA), and assurance case artefacts required to achieve safety certification can be automatically generated with the support the model-based safety analysis and assurance case construction techniques. / Engenharia de Linha de Produtos de Software (ELPS) contribui para a redução dos custos de desenvolvimento e de manutenção, a melhoria do time-to-market, e o aumento da qualidade de produtos desenvolvidos a partir de uma família de produtos por meio do reuso sistemático dos ativos principais da linha de produtos. A ELPS vem sendo utilizada com sucesso no desenvolvimento de sistemas embarcados críticos, especificamente nos domínios de sistemas automotivos e aeroespaciais. Sistemas embarcados críticos devem ser desenvolvidos de acordo com os requisitos definidos em padrões de segurança, que demandam a produção de artefatos de análise de segurança, árvores de falhas e casos de segurança. Entretanto, a realização de atividades de análise de segurança, análise de árvores de falhas e construção de casos de segurança de forma manual para cada produto de uma linha de produtos é uma tarefa demorada e propensa a erros. O gerenciamento de variabilidade em artefatos de análise de segurança pode ser automatizado com o apoio de técnicas de gerenciamento de variabilidades. Em virtude de safety ser uma propriedade dependente de contexto, a variabilidade no projeto e contexto inerente uma linha de produtos software impacta na definição de propriedades de segurança do sistema, modificando as ameaças à segurança do sistema, suas causas e riscos, medidas de mitigação aplicáveis, e resultados de análise de árvore de falhas. Dessa forma, gerenciar variabilidades em artefatos relacionados à safety em diferentes níveis de abstração aumenta a complexidade do modelo de variabilidade mesmo com o apoio de técnicas de gerenciamento de variabilidades. Para alcançar o equilíbrio eficaz entre os benefícios e a complexidade da adoção de uma abordagem de ELPS para o desenvolvimento de sistemas embarcados críticos é necessário fazer a distinção entre artefatos de safety reusáveis, em que a variabilidade deve ser gerenciada, e artefatos de safety que devem ser gerados a partir de artefatos reusáveis. Por outro lado, tanto a indústria quanto os padrões de segurança têm reconhecido o uso de técnicas dirigidas a modelos para apoiar a análise segurança e a construção de casos de segurança. Técnicas de análise de segurança composicional e otimização de projeto, e de construção de casos de segurança dirigido a modelos vêm sendo utilizadas para apoiar a geração de artefatos de safety requeridos para certificação. O objetivo desta tese é a proposta de uma abordagem dirigida a modelos que integra técnicas de desenvolvimento dirigido a modelos, análise de segurança composicional e otimização de projeto, e construção de casos de segurança dirigido a modelos para apoiar o reuso sistemático e a geração de artefatos de safety em engenharia de linhas de produtos de sistemas embarcados críticos. A abordagem proposta reduz o esforço e os custos de análise e avaliação de segurança para produtos de uma linha de produtos, uma vez que tal análise é realizada a partir de artefatos de safety reusados. Assim, artefatos como análises de árvores de falhas e de modos de falha e efeitos, e casos de segurança requeridos para certificação podem ser gerados automaticamente com o apoio de técnicas dirigidas a modelos.

The number and complexity of the systems realizing the functionality of the machines in the automotive domain are growing. In this arises the need for a systematic way to manage their development. As the technologies advance, the vehicles introduce an increasing range of capabilities. However, they have similar functions, which have the potential to be reused. One of the widely used approaches that manages the commonality and variability of the development artifacts in a systematic manner is Product Line Engineering (PLE). Consequently, PLE reduces the time to market and the development cost. The machines, realized in the automotive domain, interact with their operators and the surrounding environment. Possible malfunctions of the machines may introduce a risk of accidents with fatal consequences. Therefore, the products should be analyzed, developed and managed in a safe manner and certified according to different relevant safety standards like ISO 15998, ISO 61508 and ISO 26262. There is a diversity of functions in a Product Line (PL). Some of them are mandatory for all machines and others are optional for some models. This gives the opportunity to combine the functions in multiple configurations. However, not all combinations are possible due to dependencies among the functions. Furthermore, the configurations should be valid from a safety perspective, and the developed products should satisfy the requirements identified during the safety analysis. The above mentioned factors emphasize the need for explicit representation of the systems' characteristics, such as commonality and variability, functional dependencies and quality attributes. The purpose of the current work is to find an efficient way to satisfy this need. The scope of our research is limited to the automotive domain. In order to gain familiarity with the state of practice, we collaborated with Volvo Construction Equipment (Volvo CE) as an industrial partner. In particular, we: conducted an informal interview study with the practitioners, analyzed the requirements management tool used in Volvo CE and studied products typical for the domain in detail, examined the deliverables defined in the related domain specific safety standards. We gained knowledge on how variability is managed in an industrial context today, which safety aspects need to be considered and how functional safety artifacts are managed with regards to variability. We synthesized the characteristics that are explicitly represented during the development and safety certification of the products in a safety-critical product line. We identified the challenges that the practitioners meet today and the areas that need to be improved. As a result, we formulated evaluation criteria for search and assessment of possible solutions. Subsequently we searched in the literature for different modeling techniques, that are able to respond to the industrial needs, and found the following to be relevant in our context: Feature modeling techniques consider the different variability types and dependencies among the features. Model-based development techniques can represent different views of the system on each level of the development process. Orthogonal modeling techniques extract the variability and dependencies in a different view. Furthermore, we evaluated the methods found during the literature study, based on the proposed criteria. We concluded that the examined techniques alone cannot represent all characteristics needed to support the development of a safety-critical product line, especially the impact of the variability on the safety and vice versa. However, each of them focuses on the presentation of certain aspect of the product line, which can help in building a more complete representation. Thus we focused on the approaches that may be extended and integrated into a complete solution. As a result, we propose a model and graphical notation for variability management in safety-critical product lines, which takes the identified industrial needs into account. The concept is depicted graphically by several model-based diagrams, which represent the different aspects of the product line, on each development level. Special attention is paid to the representation of the safety and variability aspects of the systems. The method is exemplified on an industrial example, in order to show how it achieves the defined goals.

The diploma thesis deals with usage of statistical methods to assure capability of production process. The theoretical part includes the definition of quality management, basic statistical concepts and statistical process control. The practical part presents basic information about the company P & L, spol. s r. o. and analyzes the production process of selected parts. The tools of statistical process control are applied and measures to assure capability of production process are proposed.

Mobile applications are developed to run on fast-evolving platforms, such as Android or iOS. Respective mobile devices are heterogeneous concerning hardware (e.g., sensors, displays, communication interfaces) and software, especially operating system functions. Software vendors cope with platform evolution and various hardware configurations by abstracting from these variable assets. However, they cannot be sure about their assumptions on the inner conformance of all device parts and that the application runs reliably on each of them—in consequence, comprehensive testing is required. Thereby, in testing, variability becomes tedious due to the large number of test cases required to validate behavior on all possible device configurations. In this paper, we provide remedy to this problem by combining model-based testing with variability concepts from Software Product Line engineering. For this purpose, we use feature-based test modeling to generate test cases from variable operational models for individual application configurations and versions. Furthermore, we illustrate our concepts using the commercial mobile application “runtastic” as example application.

Made available in DSpace on 2014-12-17T15:47:04Z (GMT). No. of bitstreams: 1 FellipeAA_TESE.pdf: 3718694 bytes, checksum: ce9f8bd2cb41f94ca63270d9cfe0484c (MD5) Previous issue date: 2013-08-19 / Nowadays, the importance of using software processes is already consolidated and is considered fundamental to the success of software development projects. Large and medium software projects demand the definition and continuous improvement of software processes in order to promote the productive development of high-quality software. Customizing and evolving existing software processes to address the variety of scenarios, technologies, culture and scale is a recurrent challenge required by the software industry. It involves the adaptation of software process models for the reality of their projects. Besides, it must also promote the reuse of past experiences in the definition and development of software processes for the new projects. The adequate management and execution of software processes can bring a better quality and productivity to the produced software systems. This work aimed to explore the use and adaptation of consolidated software product lines techniques to promote the management of the variabilities of software process families. In order to achieve this aim: (i) a systematic literature review is conducted to identify and characterize variability management approaches for software processes; (ii) an annotative approach for the variability management of software process lines is proposed and developed; and finally (iii) empirical studies and a controlled experiment assess and compare the proposed annotative approach against a compositional one. One study a comparative qualitative study analyzed the annotative and compositional approaches from different perspectives, such as: modularity, traceability, error detection, granularity, uniformity, adoption, and systematic variability management. Another study a comparative quantitative study has considered internal attributes of the specification of software process lines, such as modularity, size and complexity. Finally, the last study a controlled experiment evaluated the effort to use and the understandability of the investigated approaches when modeling and evolving specifications of software process lines. The studies bring evidences of several benefits of the annotative approach, and the potential of integration with the compositional approach, to assist the variability management of software process lines / A ind?stria de software encontra-se, nos dias de hoje, em um cen?rio altamente din?mico, o qual reflete o mundo dos neg?cios e a sociedade como um todo. A demanda por sistemas de software ?, dessa forma, cada vez mais crescente e visa atender a diferentes dom?nios. Nesse cen?rio, onde sistemas de software complexos precisam ser desenvolvidos com um excelente n?vel de qualidade e consumindo menor quantidade de recursos; aumenta a import?ncia da defini??o de processos de software. Por?m, tais processos necessitam ser devidamente adaptados aos contextos espec?ficos de cada projeto, de forma a garantir a qualidade dos produtos de software desenvolvidos bem como o uso eficaz dos recursos dispon?veis. Para que essa adapta??o dos processos de software ocorra de forma eficaz, ? necess?rio promover a reutiliza??o de especifica??es de processos j? existentes, bem como experi?ncias e pr?ticas de sucesso passadas. Este trabalho explora a ado??o de t?cnicas de engenharia de linha de produtos de software de forma a promover a ger?ncia de variabilidades de fam?lias de processos de software. Para um melhor entendimento do problema em quest?o foi realizada uma revis?o sistem?tica da literatura, a qual identificou um conjunto de abordagens para a ger?ncia de variabilidades em processos de software e suas principais caracter?sticas. Tamb?m foi realizada a proposta de uma abordagem anotativa para a ger?ncia de variabilidades em processos de software, bem como um estudo explorat?rio visando a concretiza??o dessa abordagem e a implementa??o de um prot?tipo de ferramenta para auxiliar na aplica??o da mesma. A abordagem anotativa proposta foi, ent?o, avaliada e comparada com a abordagem composicional do EPF Composer. Tais avalia??es foram conduzidas por meio da realiza??o de estudos emp?ricos e um experimento controlado. Nos estudos emp?ricos as abordagens foram avaliadas: (i) qualitativamente de acordo com um conjunto de crit?rios de an?lise da especifica??o de suas variabilidades; e (ii) quantitativamente por meio da compara??o de valores obtidos para m?tricas de modularidade, tamanho e complexidade para as especifica??es de uma mesma linha de processo usando as abordagens anotativa e composicionais. O experimento controlado teve como objetivo comparar as abordagens anotativa e composicional sob a perspectiva do esfor?o e entendimento das abordagens quando utilizadas na especifica??o de variabilidades em uma linha de processos de software. Os estudos evidenciaram diversos benef?cios proporcionados pela abordagem anotativa no contexto de linhas de processos de software e seu potencial de integra??o com abordagens composicionais para auxiliar na modelagem de variabilidades em processos de software

Made available in DSpace on 2016-06-02T19:06:22Z (GMT). No. of bitstreams: 1 6616.pdf: 3224245 bytes, checksum: 3bea5c064e483543e0961a78c51613d2 (MD5) Previous issue date: 2014-10-20 / Software as a Service (SaaS) represent a form of software distribution on demand and accessible via the Internet. The development of SaaS enables service users (tenants) to benefit from the low cost of deployment and maintenance. The Multi-Tenant (MT) architecture is often used in the development of SaaS, it allows the sharing of software and hardware resources, providing cost savings to the costumers and the service provider. A challenge that the SaaS developer has is to keep sharing the instance of the software in scenarios with tenants who have differing needs. In this project, to address the variability of tenants in SaaS MT were set some patterns, based on Software Product Lines techniques for customizing user interfaces, data, processes and permissions. A framework called FoSaaS (Framework of Software as a Service) has also been developed to support the use of patterns, providing support to developers in SaaS MT coding. In addition to allowing the customization of SaaS MT, experiments in this project indicated that patterns improve reuse, quality and productivity in developed SaaS MT. The applicability of the patterns was evidenced through real projects in developing commercial applications. / Softwares como um Serviço (SaaS) representam uma forma de distribuição de software sob demanda e acessíveis via Internet. O desenvolvimento de SaaS possibilita aos consumidores do serviço (tenants) se beneficiarem do baixo custo de implantação e manutenção. A arquitetura Multi-Tenant (MT) é frequentemente utilizada no desenvolvimento de SaaS, pois permite o compartilhamento de recursos de software e hardware, proporcionando a redução de custos ao consumidor e ao fornecedor do serviço. Um desafio que o desenvolvedor de SaaS tem é o de manter o compartilhamento da instância do software em cenários com tenants que possuem necessidades divergentes. Neste projeto, para tratar a variabilidade dos tenants em SaaS MT foram criados alguns padrões, com base em técnicas de linhas de produtos de software, para customização de interfaces de usuários, dados, processos e permissões. Um framework denominado FoSaaS (Framework of Software as a Service) também foi desenvolvido para apoiar o uso dos padrões criados fornecendo apoio aos desenvolvedores na codificação de SaaS MT. Além de permitir a customização de SaaS MT, experimentos realizados neste projeto indicaram que os padrões melhoram o reúso, a qualidade e a produtividade dos SaaS MT desenvolvidos. A aplicabilidade dos padrões foi evidenciada por meio da realização de projetos reais no desenvolvimento de aplicações comerciais.

A recent trend in software industry is to provide enterprise applications in the cloud that are accessible everywhere and on any device. As the market is highly competitive, customer orientation plays an important role. Companies therefore start providing applications as a service, which are directly configurable by customers in an online self-service portal. However, customer configurations are usually deployed in separated application instances. Thus, each instance is provisioned manually and must be maintained separately. Due to the induced redundancy in software and hardware components, resources are not optimally utilized. A multi-tenant aware application architecture eliminates redundancy, as a single application instance serves multiple customers renting the application. The combination of a configuration self-service portal with a multi-tenant aware application architecture allows serving customers just-in-time by automating the deployment process. Furthermore, self-service portals improve application scalability in terms of functionality, as customers can adapt application configurations on themselves according to their changing demands. However, the configurability of current multi-tenant aware applications is rather limited. Solutions implementing variability are mainly developed for a single business case and cannot be directly transferred to other application scenarios. The goal of this thesis is to provide a generic framework for handling application variability, automating configuration and reconfiguration processes essential for self-service portals, while exploiting the advantages of multi-tenancy. A promising solution to achieve this goal is the application of software product line methods. In software product line research, feature models are in wide use to express variability of software intense systems on an abstract level, as features are a common notion in software engineering and prominent in matching customer requirements against product functionality. This thesis introduces a framework for feature-based configuration management of reconfigurable cloud applications. The contribution is three-fold. First, a development strategy for flexible multi-tenant aware applications is proposed, capable of integrating customer configurations at application runtime. Second, a generic method for defining concern-specific configuration perspectives is contributed. Perspectives can be tailored for certain application scopes and facilitate the handling of numerous configuration options. Third, a novel method is proposed to model and automate structured configuration processes that adapt to varying stakeholders and reduce configuration redundancies. Therefore, configuration processes are modeled as workflows and adapted by applying rewrite rules triggered by stakeholder events. The applicability of the proposed concepts is evaluated in different case studies in the industrial and academic context. Summarizing, the introduced framework for feature-based configuration management is a foundation for automating configuration and reconfiguration processes of multi-tenant aware cloud applications, while enabling application scalability in terms of functionality.