EQ-Mine: Predicting Short-Term Defects for Software Evolution

We use 63 features extracted from sources such as versioning and issue tracking systems to predict defects in short time frames of two months. Our multivariate approach covers aspects of software projects such as size, team structure, process orientation, complexity of existing solution, difficulty of problem, coupling aspects, time constrains, and testing data. We investigate the predictability of several severities of defects in software projects. Are defects with high severity difficult to predict? Are prediction models for defects that are discovered by internal staff similar to models for defects reported from the field?

We present both an exact numerical prediction of future defect numbers based on regression models as well as a classification of software components as defect-prone based on the C4.5 decision tree. We create models to accurately predict short-term defects in a study of 5 applications composed of more than 8.000 classes and 700.000 lines of code. The model quality is assessed based on 10-fold cross validation.