For many software projects, keeping requirements on track needs an effective and efficient path from data to decision. Visual analytics creates such a path that enables the human to extract insights by interacting with the relevant information. While various requirements visualization techniques exist, few have produced end-to-end values to practitioners. In this dissertation, we advance the literature on visual requirements analytics by characterizing its key components and relationships in a framework. We follow the goal-question-metric paradigm to define the framework by teasing out five conceptual goals (user, data, model, visualization, and knowledge), their specific operationalizations, and their interconnections. The framework allows us to not only assess existing approaches, but also create tool enhancements in a principled manner. We evaluate our enhanced tool supports both qualitatively and quantitatively. First, we evaluate our tool supports qualitatively through a case study where massive, heterogeneous, and dynamic requirements are processed, visualized, and analyzed. Working together with practitioners on a contemporary software project within its real-life context leads to the main ending that visual analytics can help tackle both open-ended visual exploration tasks and well-structured visual exploitation tasks in requirements engineering. In addition, the study helps the practitioners to reach actionable decisions in a wide range of areas relating to their project, ranging from theme and outlier identification, over requirements tracing, to risk assessment. Overall our work illuminates how the data-to-decision analytical capabilities could be improved by the increased interactivity of requirements visualization. Although many new visual analytics tools, techniques and methods are being developed, still there is a lack of understanding of how to evaluate the performance of such tools. We conducted an experiment to assess the performance (time and correctness) of our visual analytics tool support in solving requirements engineering tasks. Our study provides initial evidence and insights for visual analytics in requirements engineering and sheds light on many challenging open questions.

[pt] No processo de desenvolvimento do software, atividades relacionadas ao Processo de Requisitos envolvem elicitação, modelagem, verificação e validação dos requisitos. O uso da linguagem natural no registro dos requisitos facilita a comunicação entre os participantes do processo, além de possibilitar que clientes e usuários validem requisitos sem necessitar de conhecimento extra. Por outro lado, na economia globalizada atual, o desenvolvimento de software por equipes geograficamente distribuídas está se tornando uma norma. Nesse cenário, atividades de verificação e validação de requisitos para um software de média ou alta complexidade podem envolver o tratamento de centenas ou milhares de requisitos. Com essa ordem de complexidade é importante que o engenheiro de software tenha apoio computacional para o desempenho adequado das atividades de aferição de qualidade. Neste trabalho estamos propondo uma estratégia que combina técnicas de processamento da linguagem natural (PLN) e agentes de software para apoiar as atividades de análise dos requisitos. Geramos visões textuais ou gráficas de grupos de requisitos relacionados; visões apóiam a análise de completude, a identificação de duplicidades e de dependências entre requisitos. Utilizamos técnicas de análise de conteúdo para apoiar a identificação de omissões em requisitos não funcionais. Também propomos uma estratégia para a construção ou atualização do léxico da aplicação, utilizando técnicas de PLN. Utilizamos agentes de software para implementar serviços que incorporam as estratégias referidas, e também para atuar como representantes dos participantes do projeto em desenvolvimento. / [en] In software development process, initial activities can involve requirements elicitation, modeling and analysis (verification and validation). The use of natural language in the register of the requirements facilitates the communication among stakeholders, besides offering possibilities to customers and users to validate requirements without extra knowledge. On the other hand, in the current global economy, software development for teams geographically distributed is becoming a rule. In this scenario, requirements verification and validation for medium or high complexity software can involve the treatment of hundreds or even thousand requirements. With this complexity order it is important to provide computational support for the software engineer execute quality activities. In this work we propose a strategy which combines natural language processing (NLP) techniques and software agents to support analysis activities. We have generated textual or graphical visions from groups of related requirements; visions help completeness analysis, identification of duplicities and dependences among requirements. We use content analysis techniques to support the identification of omissions in nonfunctional requirements. Also, we propose a strategy to construct the lexicon, using NLP techniques. We use software agents to implement web services that incorporate the related strategies, and also agents to act as personal assistants for stakeholders of the software project.