O crescente aumento da complexidade dos sistemas embarcados demanda consigo a necessidade do uso de novas abordagens que acelerem o seu desenvolvimento, como por exemplo, o desenvolvimento baseado em modelos. Essas novas abordagens buscam aumentar o nível de abstração, utilizando conceitos de orientação a objetos e UML para modelar um software embarcado. Porém, com o aumento do nível de abstração, o projetista de software embarcado não possui a ideia exata do impacto de suas decisões de modelagem em questões importantes, como desempenho, consumo de energia, entre tantas outras que são de suma importância em um projeto embarcado. Dessa forma, se fazem necessárias técnicas de análise e/ou estimação de projeto que, em um ambiente de desenvolvimento mais abstrato, possam auxiliar o projetista a tomar melhores decisões nas etapas inicias de projeto, garantindo assim, as funcionalidades (requisitos funcionais) e os requisitos não funcionais do sistema embarcado. Neste trabalho, propõe-se estimar os requisitos não funcionais de um sistema embarcado a partir de informações (métricas) extraídas das etapas iniciais do projeto. Pretende-se com isso auxiliar o projetista na exploração do espaço de projeto já nos estágios iniciais do processo de desenvolvimento, através de uma rápida realimentação sobre o impacto de uma decisão de projeto no desempenho da aplicação em uma dada plataforma de execução. Os resultados experimentais mostram a aplicabilidade da abordagem, principalmente para um ambiente de evolução e manutenção de projetos de software, onde se tem um histórico de métricas de aplicações semelhantes para serem usadas como dados de treinamento. Neste cenário, a abordagem proposta possui acurácia de pelo menos 98% para as estimativas apresentadas ao projetista. Em um cenário heterogêneo, assumindo o uso da metodologia em um sistema diferente daquele usado para treinamento, a acurácia do método de estimação cai para pelo menos 80%. / The increasing complexity of embedded systems demands the use of new approaches to accelerate their development, such as model-driven engineering. Such approaches aim at increasing the level of abstraction using concepts such as object-orientation and UML for modeling the embedded software. However, with the increase of the abstraction level, the embedded software developer looses controllability and predictability over important issues such as performance, power dissipation and memory usage for a specific embedded platform. Thus, new design estimation techniques that can be used in the early development stages become necessary. Such a strategy may help the designer to make better decisions in the early stages of the project, thus ensuring the final system meets both functional and non-functional requirements. In this work, we propose an estimation technique of non-functional requirements for embedded systems, based on data (metrics) extracted from early stages of the project. The proposed methodology allows to better explore different design options in the early steps of software development process and can therefore provide a fast and yet accurate feedback to the developer. Experimental results show the applicability of the approach, particularly for software evolution and maintenance, which has a history of similar applications metrics to be used as training data. In this scenario, the accuracy of the estimation is at least of 98%. In a heterogeneous scenario, where the estimation is performed for a system that is different from the one used during training, the accuracy drops to 80%.

Métricas de código-fonte não são novidade, mas ainda não têm sido bem exploradas no desenvolvimento de software. A maioria das ferramentas de métricas mostra valores numéricos isolados, que não são fáceis de entender porque a interpretação deles depende do contexto da implementação. Esta dissertação apresenta o software livre Kalibro Metrics, que foi desenvolvido com o objetivo de melhorar a legibilidade de métricas de código-fonte. Kalibro, ao contrário das outras ferramentas, permite que o próprio usuário crie configurações de intervalos associados a avaliações qualitativas, incluindo comentários e recomendações. Usando essas configurações, o Kalibro mostra resultados de métricas de modo amigável, ajudando: arquitetos de software a detectar falhas de projeto; gerentes de projetos a controlar a qualidade de código-fonte; usuários de software e pesquisadores a comparar características específicas do código-fonte de vários projetos. Essas configurações podem ser compartilhadas e utilizadas para intermediar discussões voltadas à evolução de critérios de avaliação baseados em métricas de código-fonte. / Source code metrics are not new, but they have not yet been fully explored in software development. Most metric tools show isolated numeric values, which are not easy to understand because their interpretation depends on the implementation context. This dissertation presents the free software Kalibro Metrics, which was developed to improve readability of source code metrics. Kalibro, unlike the current tools, allows the user himself to create configurations of thresholds associated with qualitative evaluation, including comments and recommendations. Using these configurations, Kalibro shows metric results in a friendly way, helping: software architects to spot design flaws; project managers to control source code quality; software users and researchers to compare specific source code characteristics across software projects. These configurations can be shared and used to mediate discussions focused on the evolution of assessment criteria based on source code metrics.

Os sistemas de modelagem de distribuição provável de espécie são utilizados para identificar regiões onde há maior probabilidade de uma determinada espécie viver, baseado nas características ambientais de localizações onde é conhecido que há presença daquela espécie. Estes sistemas requerem computação de alto desempenho devido à grande quantidade de dados que precisam ser processados para se gerar um modelo com a distribuição provável. Um momento importante do processo de modelagem de distribuição de espécies é a coleta dos dados, no qual os pesquisadores vão a campo para identificar alguns pontos de presença ou ausência, no entanto este processo é feito de forma ainda manual. Este trabalho apresenta uma proposta de automação deste processo por meio da utilização de dispositivos móveis e arquitetura SOA. Historicamente, os sistemas que utilizam arquiteturas orientadas a serviço não consideram fortemente as limitações inerentes aos dispositivos móveis, tais como poder de processamento, capacidade de armazenamento e duração da bateria. A falta de uma infra-estrutura de referência para estes sistemas pode ser apontada como uma das causas deste problema. Assim, é proposta uma infra-estrutura de desenvolvimento para sistemas móveis que utilizam uma arquitetura orientada a serviços voltada à experiência do usuário. Esta infra-estrutura tem especial atenção a como as restrições dos sistemas móveis influenciam tanto a arquitetura de software quanto a apresentação dos serviços para o usuário final. Disserta-se sobre fatores e questões relevantes ao projeto de sistemas de natureza móvel sugerindo a sua consideração durante a elaboração de projetos semelhantes. São propostos também um conjunto de métricas para avaliação do desempenho para a realização de experimentos com o objetivo de validar os aspectos de usabilidade e arquitetura, além de identificar modificações na infra-estrutura proposta. / Species distribution modeling system are used to identify regions where there is the probability to a species survive, based on the environmental characteristics where there is for sure presence of a species. Those systems require high performance computation due the large amount of data that are processed in order to create the distribution model. An important moment of the modeling process is the data collecting, when the researchers go field to identify the localizations of presence or absence, but this process is still done manually. This paper presents a proposal for automating this process through the use of mobile devices and SOA architecture. Historically, systems using service oriented architectures do not consider strongly the limitations of mobile devices such as processing power, storage capacity and duration of battery. The lack of an infrastructure of reference for these systems can be considered one of the causes of this problem. Thus, we propose an infrastructure development for mobile systems using a service-oriented architecture focused on user experience. This infrastructure has special attention to the restrictions of mobile systems influence both the software architecture as the presentation of services to the end user. Mobile related issues are discussed suggesting its consideration during the development of similar projects. Also, it is proposed a set of metrics for performance evaluation to carry out experiments aimed at validating the architecture and usability aspects, and identify changes in the proposed infrastructure.

The notion of maximizing software reuse among the family of products has gained considerable attention in the last decade. Lots of research has been done on designing and managing the commonalities and variabilities between the products. However, very few metrics have been developed to assist architects in designing product line architectures. The structure of the product line holds immense importance towards increasing the life span of the product line. Since many of the product line architecture design methodologies follow a component based approach, it seems logical to attempt to adapt the component based metrics to the product line domain. In this thesis, we attempt to derive metrics that quantify the structural quality of product line architecture. / +92-42-5727639

Capturing the quality of software and detecting sections for further scrutiny within are of high interest for industry as well as for education. Project managers request quality reports in order to evaluate the current status and to initiate appropriate improvement actions and teachers feel the need of detecting students which need extra attention and help in certain programming aspects. By means of software measurement software characteristics can be quantified and the produced measures analyzed to gain an understanding about the underlying software quality. In this study, the technique of code profiling (being the activity of creating a summary of distinctive characteristics of software code) was inspected, formulized and conducted by means of a sample group of 19 industry and 37 student programs. When software projects are analyzed by means of software measurements, a considerable amount of data is produced. The task is to organize the data and draw meaningful information from the measures produced, quickly and without high expenses. The results of this study indicated that code profiling can be a useful technique for quick program comparisons and continuous quality observations with several application scenarios in both industry and education.

Following the success of software engineering design patterns, security patterns are a promising approach to aid in the design and development of more secure software systems. At the same time, recent work on aspect-oriented programming (AOP) suggests that the cross-cutting nature of software security concerns makes it a good candidate for AOP techniques. This work uses a set of software metrics to evaluate and compare object-oriented and aspect-oriented implementations of five security patterns--Secure Base Action, Intercepting Validator, Authentication Enforcer, Authorization Enforcer, and Secure Logger. Results show that complete separation of concerns was achieved with the aspect-oriented implementations and the modularity of the base application was improved, but at a cost of increased complexity in the security pattern code. In most cases the cohesion, coupling, and size metrics were improved for the base application but worsened for the security pattern package. Furthermore, a partial aspect-oriented solution, where the pattern code is decoupled from the base application but not completely encapsulated by the aspect, demonstrated better modularity and reusability than a full aspect solution. This study makes several contributions to the fields of aspect-oriented programming and security patterns. It presents quantitative evidence of the effect of aspectization on the modularity of security pattern implementations. It augments four existing security pattern descriptions with aspect-oriented solution strategies, complete with new class and sequence diagrams based on proposed aspect-oriented UML extensions. Finally, it provides a set of role-based refactoring instructions for each security pattern, along with a proposal for three new basic generalization refactorings for aspects.

La plupart des métriques de qualité logicielle mesurables sont actuellement basées sur des mesures bas niveau, telles que la complexité cyclomatique, le nombre de lignes de commentaires ou le nombre de blocs dupliqués. De même, la qualité de l'ingénierie logicielle est davantage liée à des facteurs techniques ou de gestion, et devrait fournir des indicateurs utiles pour les exigences de qualité. Actuellement, l'évaluation de ces exigences de qualité n'est pas automatisée, elle n'est pas validée empiriquement dans des contextes réels et l'évaluation est définie sans tenir compte des principes de la théorie de la mesure. Par conséquent, il est difficile de comprendre où et comment améliorer le logiciel suivant le résultat obtenu. Dans ce domaine, les principaux défis consistent à définir des métriques adéquates et utiles pour les exigences de qualité, les documents de conception de logiciels et autres artefacts logiciels, y compris les activités de test.Les principales problématiques scientifiques abordées dans cette thèse sont les suivantes: définir des mesures et des outils de support pour mesurer les activités d'ingénierie logicielle modernes en termes d'efficacité et de qualité. La seconde consiste à analyser les résultats de mesure pour identifier quoi et comment s'améliorer automatiquement. Le dernier consiste en l'automatisation du processus de mesure afin de réduire le temps de développement. Une telle solution hautement automatisée et facile à déployer constituera une solution révolutionnaire, car les outils actuels ne le prennent pas en charge, sauf pour une portée très limitée. / Most of the measurable software quality metrics are currently based on low level metrics, such as cyclomatic complexity, number of comment lines or number of duplicated blocks. Likewise, quality of software engineering is more related to technical or management factoid, and should provide useful metrics for quality requirements. Currently the assessment of these quality requirements is not automated, not empirically validated in real contexts, and the assessment is defined without considering principles of measurement theory. Therefore it is difficult to understand where and how to improve the software following the obtained result. In this domain, the main challenges are to define adequate and useful metrics for quality requirements, software design documents and other software artifacts, including testing activities.The main scientific problematic that are tackled in this proposed thesis are the following : defining metrics and its supporting tools for measuring modern software engineering activities with respect to efficiency and quality. The second consists in analyzing measurement results for identifying what and how to improve automatically. The last one consists in the measurement process automation in order to reduce the development time. Such highly automated and easy to deploy solution will be a breakthrough solution, as current tools do not support it except for very limited scope.

The main purpose of exception handling mechanisms is to improve software robustness by handling exceptions when they occur. However, empirical evidence indicates that improper implementation of exception handling code can be a source of faults in software systems. There is still limited empirical knowledge about the relationship between exception handling code and defects. In this dissertation, we present three case studies investigating defect densities of exception handling code. The results show that in every system under study, the defect density of exception handling code was significantly higher than the defect density of overall source code and normal code. The ability to predict the location of faults can assist in directing quality enhancement efforts to modules that are likely to have faults. This information can be used to guide test plans, narrow the test space, and improve software quality. We hypothesize that complicated exception handling structure is a predictive factor that is associated with defects. To the best of our knowledge, no study has addressed the relationship between the attributes of exception handling method call structures and defect occurrence, nor has prior work addressed fault prediction. We extract exception-based software metrics from the structural attributes of exception handling call graphs. To find out whether there are patterns of relationship between exception-based software metrics and fault-proneness, we propose a defect prediction model using exception handling call structures. We apply the J48 algorithm, which is the Java implementation of the C4.5 algorithm, to build exception defect prediction models. In two out of three systems under study, the results reveal that there are logical patterns of relationships between most class level exception metrics and fault-proneness. The accuracy of our prediction models is comparable to the results of defect prediction model studies in the literature. It was observed that our approach has somewhat worse predictive accuracy when a system has low average defects per class.

In recent years, there has been a surge in research on theimpact of architectural smells on software maintainability.Maintainability in turn encompasses several other qualityattributes as sub-characteristics, such as modularity andtestability. However, the empirical evidence establishing aclear relationship between these quality attributes andarchitectural smells has been lacking. This study aims to fillthis gap by examining the correlation between sevenarchitectural smells and testability/modularity across 378versions of eight open-source projects. A self-developedtool—ASAT—was used to collect data on architecturalsmells and metrics relating to modularity and testability. Thecollected data was analyzed to reveal correlations at both theproject-level and within packages. Contrary to expectations,the findings show that, generally, there is no negativecorrelation between smells and modularity at the projectlevel, except for the Dense Structure smell. Remarkably,project-level testability showed the opposite result.However, a rival explanation proposes that the increasingsize of a project may be a stronger factor in this relationship.Similarly, package-level smells, as a whole, did not exhibit anegative correlation with testability. However, most smellsdemonstrated a stronger negative relationship with thequality attributes they were claimed to impair, incomparison to their counterparts. This empirical evidencesubstantiates the assertion that specific architectural smellsindeed relate to distinct quality attributes, which hadpreviously only been supported by argument.

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