An Ada Software Design Evaluation

This paper discusses a metrics approach for analyzing software designs that helps designers engineer quality into the design product. These metrics gauge project quality as well as design complexity at all times during the design phase. The metrics are developed from primitive design metrics which are predictive, objective and automatable. The architectural design metrics used are comprised of terms related to the amount of data flowing through the module and the number of invocation sequences through the module. A detailed design metrics component takes into account the structure and complexity of a module. This paper presents empirical results to illustrate the metrics’ success in identifying stress points in a software design and demonstrate their relationship to the quality of the resulting software. To automate the calculation of the design metrics in the Rational environment, DIANA (Descriptive Intermediate Attributed Notation for Ada) was utilized. Provided in the environment are packages allowing for the traversal and retrieval of the DIANA structure. By combining the defined packages with customized packages, an Ada design metrics analysis tool was developed. This paper also discusses the automation of our metrics collection at Magnavox and introduces the concept of design balance.