Developing Fault Predictors for Evolving Software Systems

Over the past several years, we have been developing methods of predicting the fault content of software systems based on measured characteristics of their structural evolution. In previous work, we have shown there is a signipcant linear relationship between code churn, a synthesized metric, and the rate at which faults are inserted into the system in terms of number of faults per unit change in code churn. A limiting factor in this and other investigations of a similar nature has been the absence of a solid and repeatable definition of the concept of a fault. The rules for fault definition were not suflciently rigorous to provide completely unambiguous and repeatable