Requirem nts Risk and Maintainability

In order to continue to make progress in software measurement as it pertains to reliability and maintainability, we must shift the emphasis from design and code metrics to metrics that characterize the risk of making requirements changes. By doing so we can improve the quality of delivered software, because defects related to problems in requirements specifications will be identified early in the life cycle. We provide an approach for identifying requirements change risk factors as predictors of reliability and maintainability problems. Our case example consists of twenty-four Space Shuttle change requests, nineteen risk factors, and the associated failures and software metrics. The approach can be generalized to other applications with numerical results that would vary according to application.