Transitioning Fault Prediction Models to a New Environment

We describe the application and evaluation of fault prediction algorithms to a project developed by a Swedish company that transitioned from waterfall to agile development methods. The project used two different version control systems and a separate bug tracking system during its lifetime. The algorithms were originally designed for use on systems implemented with a traditional waterfall process at American companies that maintained their project records in an integrated database system that combined bug recording and version control. We compare the performance of the original prediction model on the American systems to the results obtained in the Swedish environment in both its pre-agile and agile stages. We also consider the impact of additional variables in the model.