Software product line engineering is a common method for designing complex software systems. Feature modeling is the most common approach to specify product lines. A feature model is a feature diagram (a special tree of features) plus some crosscutting constraints. Feature modeling languages are grouped into basic and cardinality-based models. The common understanding of the semantics of feature models is a Boolean semantics. We discuss a major deficiency of this semantics and fix it by applying, in turn, modal logic, the theory of multisets, and formal language theory. In order to adequately represent the semantics of basic models, we propose a Kripke semantics and show that basic feature modeling needs a modal rather than Boolean logic. We propose two multiset based theories for cardinality-based feature diagrams, called flat and hierarchical semantics. We show that the hierarchical semantics of a given cardinality-based diagram captures all information in the diagram. We also charac- terize sets of multisets, which can provide a hierarchical semantics of some diagrams. We provide three different reduction processes going from a cardinality-based diagram to an appropriate regular expression. As for crosscutting constraints, we propose a formal language interpretation of them. We also characterize some existing analysis operations over feature models in terms of operations on the corresponding languages and discuss the relevant decidability problems. / Thesis / Doctor of Philosophy (PhD)

Die Ansprüche von Kunden an neue (Software-)Produkte wachsen stetig. Produkte sollen genau auf die einzelnen Kundenwünsche zugeschnitten sein, sodass der Kunde genau die Funktionalität erhält und bezahlt die er benötigt. Hersteller reagieren auf diese gestiegenen Ansprüche mit immer mehr Varianten in denen sie ihre Produkte ihren Kunden anbieten. Die Variantenvielfalt hat in solchem Maß zugenommen, dass selbst in Massen gefertigte Produkte heute als Unikate produziert werden können. Neue Methoden wie Produktlinienentwicklung unterstützen die Entwicklung solcher variantenreicher Systeme. Während der Aufwand für die Entwicklung neuer Varianten nun sinkt, profitiert die Qualitätssicherung nicht vom Effizienzgewinn der Entwicklung. Im Gegenteil: Insbesondere beim Test wird zunächst jede Variante wie ein einzelnes Produkt behandelt. Bei variantenreichen Systemen ist dies aufwandsbedingt jedoch nicht mehr möglich. Die in dieser Arbeit vorgestellten Testentwurfsmethoden berücksichtigen die Variantenvielfalt in besonderem Maße. Bisher wurden, nach einer Stichprobenauswahl zur Reduktion des Testaufwands, die Testfälle auf Basis der konkreten Produkte entworfen. Statt nun auf Basis konkreter Produkte werden in dieser Arbeit zwei Ansätze vorgestellt, die die Phase des Testentwurfs auf die Produktlinienebene heben. Die bei Anwendung dieser Methoden entstehenden Testfälle enthalten, je nach Inhalt, Freiheitsgrade bzgl. ihrer Anforderungen an eine Variante, sodass ein Testfall auf ein oder mehrere Varianten angewendet wird. Ausgehend von solchen Testfällen werden in dieser Arbeit neue Kriterien zur Stichprobenauswahl entwickelt. Mit diesen Kriterien kann der Umfang der Stichprobe, aber auch Eigenschaften der zu testenden Varianten bzgl. eines gegebenes Testziel optimiert werden. So ist es möglich, z.B. sehr wenige oder sehr unterschiedliche Varianten zum Test auszuwählen. Insgesamt werden in dieser Arbeit fünf Kriterien definiert und auf ihr Fehleraufdeckungspotenzial untersucht. Zu diesem Zweck werden neue Bewertungskriterien zur Fehleraufdeckungswahrscheinlichkeit von Produktlinientests etabliert. Somit ist erstmalig eine quantitative sowie qualitative Bewertung von Produktlinientests möglich. Die Ergebnisse der vorgestellten Methoden und Auswahlkriterien werden sowohl untereinander evaluiert, als auch konventionellen Testmethoden für Produktliniensysteme gegenübergestellt. An vier Beispielen unterschiedlicher Gro{\"ss}e werden die in dieser Arbeit vorgestellten Methoden evaluiert. / Consumer expectations of (software-)products are growing continuously. They demand products that fit their exact needs, so they pay only for necessary functionalities. Producers react to those demands by offering more variants of a product. Product customization has reached a level where classically mass produced goods, like cars, can be configured to unique items. New paradigms facilitate the engineering of such variant-rich systems and reduce costs for development and production. While development and production became more efficient, quality assurance suffers from treating each variant as a distinct product. In particular, test effort is affected, since each variant must be tested sufficiently prior to production. For variant-rich systems this testing approach is not feasible anymore. The methods for test design presented in this thesis overcome this issue by integrating variability into the test design process. The resulting test cases include requirements for variants, which must be fulfilled to execute the test successfully. Hence multiple variants may fulfill these requirements, each test case may be applicable to more than only one variant. Having test cases with requirements enables sampling subsets of variants for the purpose of testing. Under the assumption that each test case must be executed once, variants can be sampled to meet predefined test goals, like testing a minimal or diverse subset of variants. In this thesis, five goals are defined and evaluated by assessing the tests for their fault detection potential. For this purpose, new criteria for assessing the fault detection capability of product line tests are established. These criteria enable quantitative as well as qualitative assessment of such test cases for the first time. The results of the presented methods are compared with each other and furthermore with state of the art methods for product line testing. This comparison is carried out on four examples of different sizes, from small to industry-grade.

Linhas de Produtos de Software (LPS) abstraem a semelhança entre produtos e envolvem o conceito de reúso de software para desenvolver software em larga escala com mais rapidez e qualidade. O reúso dos artefatos em uma LPS é planejado e executado desde sua concepção, sendo assim possível armazenar esses artefatos em um repositório (núcleo de ativos reusáveis) para utilização posterior. Porém, ao se construir um repositório para uma certa LPS, este atende apenas às especificações desta arquitetura e não promove o reúso desses ativos em outras LPS, causando uma certa perda no potencial de reusabilidade dos ativos produzidos e armazenados. Além disso, a definição e os dados da execução do processo de desenvolvimento dessas LPS também não são armazenados prevendo o reúso, o que gera retrabalho para definir e instanciar um processo de software sempre que uma nova LPS é criada. Neste contexto, este trabalho tem por objetivo apresentar uma abordagem baseada em um conjunto de serviços para promover o amplo reúso de ativos produzidos e de elementos de processo utilizados, além de facilitar a criação e o desenvolvimento de linha de produtos de software, permitindo o gerenciamento do núcleo de ativos reusáveis. Por possuir uma interface baseada em serviços, esta abordagem poderá ser incorporada também a outros ambientes. Para validar a abordagem, verificar vantagens e sugerir melhorias, foi conduzida uma prova de conceito com sua aplicação. Os resultados dessa prova comprovaram a viabilidade da abordagem em cumprir os objetivos propostos. / Software Product Lines (SPL) extract the similarity among products and use the software reuse concept to produce large-scale software with increased quality and reduction in the development time. Reuse in SPL is planned and executed since the beginning for each artifact resulting from the development process, and then these artifacts are stored in a repository (reusable core assets) for later use. However, when a repository is built for a specific SPL, it supports only the specifications for that architecture and do not promote the reuse of these assets among distinct SPL, which inhibits their reuse potential. In addition, the definition and execution data of the development process applied are not stored properly for reuse, which causes a re-work to define and instantiate a software process when creating a new SPL. In this context, this work aims at present a service-based approach to promote the wide reuse of the produced assets and process elements, also to facilitate the creation and the management of SPL and to allow the management of the reusable core assets. Once this approach has a service-based interface, it can be embedded into other environments. In order to validate this approach, point out advantages and suggest improvements, a concept proof was performed applying it. The results of this proof ensured the approach viability to fulfill the proposed goals.

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.

Os geradores de aplicação são ferramentas que recebem uma especificação de software, validam essa especificação e geram artefatos automaticamente. Os geradores de aplicação podem trazer benefícios em termos de produtividade por gerarem automaticamente artefatos de baixo nível com base em especificações de nível mais alto. Um dos problemas dos geradores de aplicação é o seu alto custo de desenvolvimento. Os geradores de aplicação configuráveis são adaptados para fornecer apoio em domínios específicos, ou seja, são considerados meta-geradores utilizados para obter geradores de aplicação específicos. Este trabalho delineia um processo de desenvolvimento com geradores confi- guráveis, define a arquitetura e as características de um gerador configurável e apresenta a ferramenta Captor, que é um gerador de aplicação configurável desenvolvido para facilitar a construção de geradores específicos. Três estudos de caso nos quais a Captor é configurada para domínios de aplicação específi- cos são apresentados: persistência de dados, gestão de recursos de negócios e bóias náuticas / Application generators are tools that receive as input a software specification, validate it and automatically generate artifacts based on it. Application generators can bring several benefits in terms of productivity, as they automatically generate low-level artifacts based on higher abstraction level specifications. A major concern of application generators is their high development cost. Con- figurable application generators are those generators that can be adapted to give support in specific domains, i.e., they are considered as meta-generators through which it is possible to obtain specific application generators. This work presents an approach for software development supported by configurable application generators. It defines the architecture and main features of a configurable application generator and presents Captor, which is a configurable application generator developed to ease the creation of specific generators. Three case studies were conducted to show the configuration of the Captor tool to different application domains: objects persistence, business resource management and floating weather stations.

L'analyse du domaine vise à identifier et organiser les caractéristiques communes et variables dans un domaine. Dans la pratique, le coût initial et le niveau d'effort manuel associés à cette analyse constituent un obstacle important pour son adoption par de nombreuses organisations qui ne peuvent en bénéficier. La contribution générale de cette thèse consiste à adopter et exploiter des techniques de traitement automatique du langage naturel et d'exploration de données pour automatiquement extraire et modéliser les connaissances relatives à la variabilité à partir de documents informels. L'enjeu est de réduire le coût opérationnel de l’analyse du domaine. Nous étudions l'applicabilité de notre idée à travers deux études de cas pris dans deux contextes différents: (1) la rétro-ingénierie des Modèles de Features (FMs) à partir des exigences réglementaires de sûreté dans le domaine de l’industrie nucléaire civil et (2) l’extraction de Matrices de Comparaison de Produits (PCMs) à partir de descriptions informelles de produits. Dans la première étude de cas, nous adoptons des techniques basées sur l’analyse sémantique, le regroupement (clustering) des exigences et les règles d'association. L'évaluation de cette approche montre que 69% de clusters sont corrects sans aucune intervention de l'utilisateur. Les dépendances entre features montrent une capacité prédictive élevée: 95% des relations obligatoires et 60% des relations optionnelles sont identifiées, et la totalité des relations d'implication et d'exclusion sont extraites. Dans la deuxième étude de cas, notre approche repose sur la technologie d'analyse contrastive pour identifier les termes spécifiques au domaine à partir du texte, l'extraction des informations pour chaque produit, le regroupement des termes et le regroupement des informations. Notre étude empirique montre que les PCMs obtenus sont compacts et contiennent de nombreuses informations quantitatives qui permettent leur comparaison. L'expérience utilisateur montre des résultats prometteurs et que notre méthode automatique est capable d'identifier 43% de features correctes et 68% de valeurs correctes dans des descriptions totalement informelles et ce, sans aucune intervention de l'utilisateur. Nous montrons qu'il existe un potentiel pour compléter ou même raffiner les caractéristiques techniques des produits. La principale leçon à tirer de ces deux études de cas, est que l’extraction et l’exploitation de la connaissance relative à la variabilité dépendent du contexte, de la nature de la variabilité et de la nature du texte. / Domain analysis is the process of analyzing a family of products to identify their common and variable features. This process is generally carried out by experts on the basis of existing informal documentation. When performed manually, this activity is both time-consuming and error-prone. In this thesis, our general contribution is to address mining and modeling variability from informal documentation. We adopt Natural Language Processing (NLP) and data mining techniques to identify features, commonalities, differences and features dependencies among related products. We investigate the applicability of this idea by instantiating it in two different contexts: (1) reverse engineering Feature Models (FMs) from regulatory requirements in nuclear domain and (2) synthesizing Product Comparison Matrices (PCMs) from informal product descriptions. In the first case study, we adopt NLP and data mining techniques based on semantic analysis, requirements clustering and association rules to assist experts when constructing feature models from these regulations. The evaluation shows that our approach is able to retrieve 69% of correct clusters without any user intervention. Moreover, features dependencies show a high predictive capacity: 95% of the mandatory relationships and 60% of optional relationships are found, and the totality of requires and exclude relationships are extracted. In the second case study, our proposed approach relies on contrastive analysis technology to mine domain specific terms from text, information extraction, terms clustering and information clustering. Overall, our empirical study shows that the resulting PCMs are compact and exhibit numerous quantitative and comparable information. The user study shows that our automatic approach retrieves 43% of correct features and 68% of correct values in one step and without any user intervention. We show that there is a potential to complement or even refine technical information of products. The main lesson learnt from the two case studies is that the exploitability and the extraction of variability knowledge depend on the context, the nature of variability and the nature of text.

A importância das disciplinas de programação nas grades curriculares de cursos de computação, tanto no contexto nacional como internacional e as limitações e problemas apresentados em tais disciplinas, tem levado a um esforço significativo em pesquisas na área da Informática na Educação para propor soluções de software no domínio de ensino e aprendizagem de programação, com destaque para a adoção de soluções para a modalidade de aprendizagem eletrônica (e-learning). No entanto, é possível notar limitações nas pesquisas já conduzidas, principalmente em relação à quantidade ainda reduzida de estudos que adotam a aprendizagem móvel (m-learning) como modalidade para ensinar a programar. Observa-se, ainda, a incipiência de pesquisas que adotam metodologias provenientes da Engenharia de Software baseada em Reúso para apoiar o processo de criação de produtos de software educacionais. A adoção de tais metodologias pode permitir uma variação maior de produtos educacionais, permitindo o desenvolvimento de modo a atender um maior número de professores, instituições e domínios. Neste contexto, esta pesquisa de doutorado tem como objetivo propor e desenvolver uma infraestrutura para o desenvolvimento de aplicações educacionais móveis para o ensino de fundamentos de programação a serem utilizadas em nível superior. Para isso, diferentes soluções já existentes foram avaliadas permitindo a criação de um catálogo de requisitos educacionais móveis que serviu de artefato para o estabelecimento de uma arquitetura de linha de produtos de software (LPS) e de uma ferramenta de apoio, intitulada TANGRAM (an infrasTructure to support the development of mobile leArning applicatioNs for the teachinG and leaRning of progrAMming fundamentals), que permite a criação facilitada dos produtos dessa linha. Adicionalmente, um conjunto inicial de funcionalidades para a plataforma móvel foi desenvolvido. Para verificar a viabilidade do uso de tal infraestrutura, diversas avaliações foram conduzidas nas diferentes etapas de concepção da mesma. Ao final, foram observadas evidências preliminares de que a LPS e a ferramenta TANGRAM possibilitam a criação de aplicações educacionais móveis para serem utilizadas na mitigação de problemas no ensino e aprendizagem de fundamentos programação. Além de contribuições complementares referentes ao catálogo de requisitos para aplicações educacionais móveis, as escolhas metodológicas e tecnológicas na concepção do projeto arquitetural, e um conjunto de gestos de interação para telas sensíveis ao toque a integrar as aplicações educacionais, que possibilitam a condução de trabalhos futuros na exploração dos mesmos no que se refere à mitigação de problemas no ensino e aprendizagem de fundamentos programação. / The importance of programming disciplines in computer curricula courses worldwide has increasing the efforts of researches in informatics in education area to propose software for the mitigation of problems in programming domain, highlighting the adoption of electronic learning solutions (e-learning). Meanwhile, it is possible to identify limitations in researches that adopting other learning modalities, as mobile learning modality (m-learning) for teaching of programming. Furthermore, it is also noticed a lack of adoption of reused-based software engineering methodologies, for supporting the process of development of educational software for programming domain, in special, software product lines (SPL).The adoption of such methodologies may allow a higher variation of educational products and a higher support for a greater number of professors and institutions. In this perspective, this doctoral research aimed at the establishment of an infrastructure to support the development of m-learning applications for the teaching of programming fundamentals in undergraduates courses. For that, several software solutions in programming domain were analysed allowing the creation of a m-learning requirement catalog. Such catalog was used as the main artifact for the establishment of an SPL and a support tool entitled TANGRAM (an infrasTructure to support the development of mobile leArning applicatioNs for the teachinG and leaRning of progrAMming fundamentals). The tool was proposed to facilitate the creation of applications considering the SPLs artifacts and their management. Additionally, an initial set of features for the mobile learning applications were developed, e.g., a catalog of gestures. To investigate the viability in the use of such infrastructure, several evaluations were conducted in each phase of conception of the SPL. At the end, preliminar positive evidence indicates that both LPS and TANGRAM tool may allow the develpment of m-learning applications for the mitigation of problems in the teaching and learning of programming fundamentals. Besides, contributions related with the m-learning requirement catalog, the methods and technologies selected for the conduction of the architectural project, and a set of gesture for touchscreen interfaces were also identified, resulting in an infrastructure which may be better investigate and adopted to improve the processes of teaching and learning in the programming fundamentals domain.

<p>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.</p><p>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.</p>

En esta tesis doctoral se presenta una propuesta de Ingeniería de Requisitos (IR) para líneas de productos que integra modelos de análisis del dominio y requisitos en lenguaje natural: (1) se estudia la reutilización de requisitos textuales, definiendo un método de IR basado en reutilización de requisitos en lenguaje natural, denominado SIREN, validado en entornos industriales; se propone además una extensión de SIREN para desarrollo global de software, junto con un repositorio de amenazas y salvaguardas para la IR que se lleva a cabo en entornos globalizados; (2) se describe una evolución de SIREN con el objetivo de modelar el dominio de una línea de productos, los sistemas teleoperados para mantenimiento de cascos de buques; y (3) se plantea la integración de modelos de ingeniería del software con especificaciones de requisitos en lenguaje natural, en este orden, implicando la generación de requisitos textuales a partir de modelos. / In this doctoral thesis an approach to requirements engineering (RE) for product lines integrating domain analysis models and natural language requirements is formulated: (1) the SIREN method is defined, an RE method based on natural language requirements reuse, which has been validated in industrial environments; furthermore, a method extending SIREN to the global software development is defined based on a risks and safeguards repository concerning RE when performed in distributed environments; (2) an evolution of SIREN is proposed with the intent of modeling the software product line of the teleoperated systems for ship hull maintenance; and (3) the interest of the generation of textual requirements starting from software engineering models is corroborated and a flattening correspondence is defined which maps the domain analysis models to natural language requirements.

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.