Combining Knowledge and Metrics to Control Software Quality Factors

The LESD project (Linguistic Engineering for Software Development) aimed to develop computing tools for analysis and reasoning on functional or preliminary speciications of aerospace software written in En-glish. These tools help to control the quality of software written during the rst stage: speciication. The factors considered relevant to the quality of speciications in the LESD project are: traceability, modiiability, completeness, consistency, and veriiability. This paper deals with completeness and modiiability. In the case of completeness we present a symbolic approach to control this factor, using a Knowledge Base. Checks are based on metarequirements that try to ensure structural completeness. The concept of modiiability is based on the level of interconnection between the requirements of the speciications. Two metrics have been deened in order to measure global and local levels of interconnection.