Measuring and evaluating maintenance process using reliability, risk, and test metrics

In analyzing the stability of a maintenance process, it is important that i t not be treated in isolation from the reliability and risk of deploying th e software that result from applying the process. Furthermore, we need to c onsider the efficiency of the test effort that is a part of the process and a determinate of reliability and risk of deployment. The relationship betw een product quality and process capability and maturity has been recognized as a major issue in software engineering based on the premise that improve ments in process will lead to higher quality products. To this end, we have been investigating an important facet of process capability-stability-as d efined and evaluated by trend, change, and shape metrics, across releases a nd within a release. Our integration of product and process measurement ser ves the dual purpose of using metrics to assess and predict reliability and risk and to evaluate process stability. We use the NASA Space Shuttle flig ht software to illustrate our approach.