Software design explorer's crystal ball

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Includes bibliographical references (p. 149-154).Most of software design is redesign. Redesign in the normal course of design happens when the software becomes difficult to maintain and the problem it is intended to solve has changed. Although software redesign is necessary, frequent, and pervasive, there is a dearth of tools that help programmers do it. Instead, programmers primarily use pen and paper, away from the computer where tools could help the most. To address this shortcoming, I have developed DR. JONES, a redesign assistant for Java programs. DR. JONES diagrams the class structure of a Java program and allows the programmer to modify that design by applying refactorings. Refactorings are localized patterns of structural change intended to improve a program's design, without changing its observable behavior. With DR. JONES, the programmer can explore the design space of the program, inspect future designs as visual diagrams, and get design assistance to guide his refactoring choices. As the programmer explores designs, DR. JONES explicitly maps the design space he traverses. This map lets him revisit any prior design and branch to explore an alternative design path, without having to explicitly manage versions of the program. DR. JONES is distinguished from other refactoring tools by separating the tasks of developing an improved design through design exploration from transforming the source code to execute design changes. It does so by deriving and using an abstract representation of the program that captures the essential information needed for design exploration, while omitting its source-level details.(cont.) DR. JONES also characterizes refactorings in a novel manner suitable for interactive design exploration. Twenty-two such refactorings are incorporated into the DR. JONES prototype. This research also contributes user interface techniques for software design exploration, including multiple-level-of detail rendering for software design diagrams, and a dialogue management interface for DR. JONES' design assistance.by Mark A. Foltz.Ph.D

Augmenting IDEs with Runtime Information for Software Maintenance

Object-oriented language features such as inheritance, abstract types, late-binding, or polymorphism lead to distributed and scattered code, rendering a software system hard to understand and maintain. The integrated development environment (IDE), the primary tool used by developers to maintain software systems, usually purely operates on static source code and does not reveal dynamic relationships between distributed source artifacts, which makes it difficult for developers to understand and navigate software systems. Another shortcoming of today's IDEs is the large amount of information with which they typically overwhelm developers. Large software systems encompass several thousand source artifacts such as classes and methods. These static artifacts are presented by IDEs in views such as trees or source editors. To gain an understanding of a system, developers have to open many such views, which leads to a workspace cluttered with different windows or tabs. Navigating through the code or maintaining a working context is thus difficult for developers working on large software systems. In this dissertation we address the question how to augment IDEs with dynamic information to better navigate scattered code while at the same time not overwhelming developers with even more information in the IDE views. We claim that by first reducing the amount of information developers have to deal with, we are subsequently able to embed dynamic information in the familiar source perspectives of IDEs to better comprehend and navigate large software spaces. We propose means to reduce or mitigate the information by highlighting relevant source elements, by explicitly representing working context, and by automatically housekeeping the workspace in the IDE. We then improve navigation of scattered code by explicitly representing dynamic collaboration and software features in the static source perspectives of IDEs. We validate our claim by conducting empirical experiments with developers and by analyzing recorded development sessions

Efficient Mapping of Software System Traces to Architectural Views

Information about a software system’s execution can help a developer with many tasks, including software testing, performance tuning, and program understanding. In almost all cases, this dynamic information is reported in terms of source-level constructs, such as procedures and methods. For some software engineering tasks, source-level information is not optimal because there is a wide gap between the information presented (i.e., procedures) and the concepts of interest to the software developer (i.e., subsystems). One way to close this gap is to allow developers to investigate the execution information in terms of a higher-level, typicallyarchitectural, view. In this paper, we present an encoding technique for dynamic trace information that makes it tractable and efficient to manipulate a trace from a variety of different architecture-level viewpoints. To motivate the need for the encoding technique, we describe two tools that use the technique: a visualization tool and a path query tool. We present the encoding technique to enable the development of additional tools that manipulate dynamic information at a higher-level than source. Keywords Dynamic information, execution information, paths, software integration testing, program understanding, performance analysis, traces, encoding.

Classes-Chave em sistemas orientados a objetos: detecção e uso

Several object-oriented systems, such as Lucene, Tomcat, Javac have their respective design documented using key-classes, defined as important/central classes to understand the object-oriented design. Considering this fact, and considering that, in general, software architecture is not formally documented to help developers understanding and assessing software design, Keecle is proposed as an approach based on dynamic and static analysis for detection of key classes in a semi-automatic way. The application of filtering mechanisms on the search space of the dynamic data is proposed in order to obtain a reduced set of key classes. The approach is evaluated with fourteen proprietary and open source systems in order to verify that the found classes correspond to the key classes of the ground-truth, which is defined from the documentation or defined by the developers. The results were analyzed in terms of precision and recall, and have shown to be superior to the state-of-the-art approach. The role of key classes in assessing design has also been investigated. The organization of the key classes in a dependency graph, which highlights explicit dependency relations in the source code, was evaluated to be adequate for design comprehension and assessment. Key classes were evaluated whether they are more prone to bad smells, and whether specific types of bad smells are associated with different levels of cohesion and coupling metrics. In addition, the ownership of key classes was shown to be more concentrated in a reduced set of developers. Finally, we conducted an experimental study with students and a survey with developers to evaluate documentation based on key classes. The results indicate that the documentation based on key classes are a feasible alternative for use as complementary documentation to the existing one, or for use as main documentation in environments where documentation is not available.FAPEG - Fundação de Amparo à Pesquisa do Estado de GoiásTese (Doutorado)Vários sistemas orientados a objetos, tais como Lucene, Tomcat, Javac tem seus respectivos projetos (designs) documentados usando classes-chave, definidas como sendo classes importantes/centrais para compreender o projeto de sistemas orientados a objetos. Considerando este fato, e considerando que geralmente a arquitetura não é formalmente documentada para auxiliar os desenvolvedores a entenderem e avaliarem o projeto do software, é proposta Keecle, uma abordagem baseada em análise dinâmica e estática para detecção de classes-chave de maneira semi-automática. É proposta a aplicação de mecanismos de filtragem no espaço de busca dos dados dinâmicos, para obter um conjunto reduzido de classes-chave. A abordagem é avaliada com quatorze sistemas de código aberto e proprietários, a fim de verificar se as classes encontradas correspondem às classes-chave definidas na documentação ou definidas pelos desenvolvedores. Os resultados foram analisados em termos de precisão e recall e são superiores às abordagens da literatura. O papel das classes-chave para avaliar o projeto também foi investigado. Foi avaliado se a organização das classes-chave em um grafo de dependências, o qual destaca relações de dependência explícitas no código fonte, é um mecanismo adequado para avaliar o design. Foi analisado estatisticamente, se classes-chave são mais propensas a bad smells, e se tipos específicos de bad smells estão associados a diferentes níveis de métricas de coesão e acoplamento. Além disso, a propriedade (ownership) das classes-chave foi analisada, indicando concentração em um conjunto reduzido de desenvolvedores. Por fim, foram conduzidos um estudo experimental com estudantes e um survey com desenvolvedores para avaliar a documentação baseada em classes-chave. Os resultados demonstram que a documentação baseada em classes-chave apresenta resultados que indicam a viabilidade de uso como documentação complementar à existente ou como documentação principal em ambientes onde a documentação não está disponível

A Re-engineering approach for software systems complying with the utilisation of ubiquitous computing technologies.

The evident progression of ubiquitous technologies has put forward the introduction of new features which software systems can sustain. Several of the ubiquitous technologies available today are regarded as fundamental elements of many software applications in various domains. The utilisation of ubiquitous technologies has an apparent impact on business processes that can grant organisations a competitive advantage and improve their productivity. The change in the business processes in such organisations typically leads to a change in the underlying software systems. In addressing the need for change in the underlying software systems, this research is focused on establishing a general framework and methodology to facilitate the reengineering of software systems in order to allow the incorporation of new features which are introduced by the employment of ubiquitous technologies. Although this thesis aims to be general and not limited to a specific programming language or software development approach, the focus is on Object-Oriented software. The reengineering framework follows a systematic step-based approach, with greater focus on the reverse engineering aspect. The four stages of the framework are: program understanding, additional-requirement engineering, integration, and finally the testing and operation stage. In its first stage, the proposed reengineering framework regards the source code as the starting point to understand the system using a static-analysis based method. The second stage is concerned with the elicitation of the user functional requirements resulting from the introduction of ubiquitous technologies. In the third stage, the goal is to integrate the system’s components and hardware handlers using a developed integration algorithm and available integration techniques. In the fourth and final stage, which is discussed in a general manner only in this thesis, the reengineered system is tested and put in the operation phase. The proposed approach is demonstrated using a case study in Java to show that the proposed approach is feasible and promising in its domain. Conclusions are drawn based on analysis and further research directions are discussed at the end of the study