A Leading Indicator of Post-Release Defect Density in Refactoring-Based Software Maintenance: A Case Study

Abstract

We look to create a leading indicator to relate the trend-of-change of the post-release defect density for two consecutive releases of a software product. We propose a rational form in which the ratio of changes of each identified internal quality factor appears as a multiplicative term either at the numerator or at the de-nominator. For a collection of factors identified as interrelated to refactoring, the best formulation is found experimentally by exhaustive enumeration. In the case study that involves a maintenance phase to bring the post-release defect densities of two suites of tools down to within the organization’s upper limit, the proposed leading indicator correctly generated the desired negative correlation with the trend of changes in postrelease defect density.