Open Access

In this paper a new approach for a metrics based software visualization is presented which supports an efficient and effective quality assessment of large object-oriented software systems. It is based on the combination of software metrics data with structure information to form a virtual information space. This information space is visualized using 3D graph structures that allow to represent in a uniform way many aspects and views on it. The layout approach for these graphs uses a generic similarity measure to calculate geometric distances between the graph nodes and a force-directed mapping into 3D space. A particular strength of the approach is that the resulting geometrical structures can be well interpreted with respect to the architecture and design quality of the analysed software. Such 3D visualizations have been used successfully in several case studies for the quality assessment of industrial C++/Java projects.

In this chapter we introduce the concept of structural quality assessments for industrial software systems (especially object-oriented code). Such a quality assessment can be used both to determine the current state with respect to quality and to plan further actions, i.e. reengineering steps, process adjustments or further education of engineers in an ongoing project. The assessment itself is based on an innovative software analysis workbench that integrates multiple interdependent views on a software system into a coherent analysis environment. These views provide information on four aspects: user-defined metrics and query results with high-level information about the system, detailed cross-reference information, browsing views and diagrams to support efficient understanding of the structure. The workbench applies powerful static analysis techniques on the source code under consideration and uses it to generate, access, visualise and browse the different views and analysis results. For practical assessments the workbench is used in a well-defined process such that a first quality assessment of large systems can be done within a very short period of time. The quality assessment described here has been applied in various projects. In order to illustrate the results that such an assessment gives for project management, developers or managers of an outsourced project this paper ends with a short description of a typical example project. This is one of the projects supported jointly by SQS and the Software Systems Engineering Research Group Cottbus