Software process reengineering has become highly visible since the late 1990s. Efforts are being undertaken by organizations of all types and sizes as they attempt to deal with the challenges of quality, complexity and competitiveness. As an emerging technology, the effectiveness and potential impact of process improvement efforts have been debated, but not fully tested or validated. At the very core of this technological evolution is the idea that the quality of a software product is highly dependent on the quality of the process used for its development. This text examines contemporary theories, model, approaches and processes involved with the concept of software improvement and reengineering