Research on Software Engineering with Patterns

Several successful projects (Linux, Free-BSD, BIND, Apache, etc.) showed that the collaborative and self-organizing process of developing open source software produces reliable, high quality software. Without doubt, the open source software development process differs in many ways from the traditional development process in a commercial environment. An interesting research question is how these differences influence the adoption of traditional software engineering practices. In this chapter we investigate how design patterns, a widely accepted software engineering practice, are adopted by open source developers for documenting changes. We analyze the development process of almost 1,000 open source software projects using version control information and explore differences in pattern adoption using characteristics of projects and developers. By analyzing these differences we provide evidence that design patterns are an important practice in open source projects and that there exist significant differences between developers who use design patterns and who do not.

Using design patterns is a widely accepted method to improve software development. There are many benefits of the application of patterns claimed in the literature. The most cited claim is that design patterns can provide a common design vocabulary and therefore improve greatly communication between software designers. Most of the claims are supported by experiences reports of practitioners, but there is a lack of quantitative research concerning the actual application of design patterns and about the realization of the claimed benefits. In this paper we analyze the development process of over 1000 open source software projects using version control information. We explore this information to gain an insight into the differences of software development with and without design patterns. By analyzing these differences we provide evidence that design patterns are used for communication and that there is a significant difference between developers who use design patterns and who do not.

The purpose of this article is to promote reuse of domain knowledge by introducing patterns already in the analysis phase of the software life-cycle. We propose an outline template for analysis patterns that strongly supports the whole analysis process from the requirements analysis to the analysis model and further on to its transformation into a flexible and reusable design and implementation. As an example we develop a family of analysis patterns in this paper that deal with a series of pressing problems in cooperative work, collaborative information filtering and sharing, and knowledge management. We evaluate the reuse potential of these patterns by analyzing several components of an information system, that was developed for the Virtual University project of the Vienna University of Economics and Business Administration. The findings of this analysis suggest that using patterns in the analysis phase has the potential to reducing development time significantly by introducing reuse already at the analysis stage and by improving the interface between analysis and design phase.

The purpose of this article is twofold, first to promote the use of patterns in the analysis phase of the software life-cycle by proposing an outline template for analysis patterns that strongly supports the whole analysis process from the requirements analysis to the analysis model and further on to its transformation into a flexible design. Second we present, as an example, a family of analysis patterns that deal with a series of pressing problems in cooperative work, collaborative information filtering and sharing, and knowledge management. We present the step-by-step evolution of the analysis pattern virtual library with active agents starting with a simple pinboard.

Diese Arbeit beschäftigt sich mit Analyse Patterns, der Anwendung von Patterns in der Analysephase der Softwareentwicklung. In der Designphase werden Patterns seit einigen Jahren eingesetzt, um Expertenwissen und Wiederverwendbarkeit in den Designprozeß einfließen zu lassen. Es existiert bereits eine Fülle an solchen Design Patterns. Die Analysephase ist ein neuer Anwendungsbereich für Patterns, der bisher in der Literatur noch nicht ausreichend behandelt wurde. In dieser Arbeit wird die Anwendung des Pattern-Ansatzes in der Analysephase aufgearbeitet und konkretisiert. Analyse Patterns unterstützen den gesamten Softwareentwicklungsprozeß und helfen bekannte Probleme während der Analysephase zu lösen. Dadurch können Zeit und Kosten bei der Entwicklung neuer Softwaresysteme eingespart werden. Diese Eigenschaften von Analyse Patterns werden anhand konkreter Beispiele in einer Case Study nachgewiesen. Diese Case Study beschreibt den Einsatz von in dieser Arbeit entwickelten Analyse Pattern für Informationsmanagement anhand des Projekts Virtuelle Universität der Wirtschaftsuniversität Wien, in dem ein Internet-Informationsbroker zur Unterstützung von Lehre und Forschung realisiert wird. Die Erfahrungen aus diesem Projekt werden untersucht, und die Auswirkungen der Analyse Patterns auf Wiederverwendung bei der Softwareentwicklung und auf die Akzeptanz des resultierenden Systems werden präsentiert.