Software metrics validation: Space Shuttle flight software example

Software quality metrics have potential for helping to ensure the quality of software on large projects such as theSpace Shuttle flight software. It is feasible to validate metrics for the purpose of controlling and predicting software quality during design by validating metrics against a quality factor. Quality factors, like reliability, are of more interest to customers than metrics, like complexity. However, quality factors cannot be collected until late in a project. Therefore, the need arises to validate metrics, which developers can collect early in a project, against a quality factor. We investigate the feasibility of validating metrics for controlling and predicting quality on theSpace Shuttle. The key to the approach is the use of validated metrics for early identification and resolution of quality problems.