“…Published evaluations of software maintenance practices tend to concentrate on the narrow issue of efficiently handling change requests and bug fixes (e.g. Briand, Kim, Melo, Seaman and Basili 1998, Onoma, Tsai, Tsunoda, Suganuma and Subramanian 1995, Singer 1998, West 1996. For example, a common denominator in these papers is the emphasis that is placed on a presence of what is termed a bug tracking system, historical data base of changes, or change management.…”