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

In analyzing the stability of a maintenance process, it is important that it not be treated in isolation from the reliability and risk of deploying the software that result from applying the process. Furthermore, we need to consider the efficiency of the test effort that is a part of the process and a determinate of reliability and risk of deployment. Therefore, we integrated these factors into a unified approach. Our contribution to maintenance is the integration and measurement of these factors so that the influence of maintenance actions and test effort on the reliability of the software and the risk of deploying it can be assessed. We use a safety critical application of national visibility-the NASA Space Shuttle-as an example application of the unified approach