Software Errors and Software Maintenance Management

A management model for explaining software errors is developed and estimated. The model is used to analyze two years of error log data at a commercial site. The focus is on identifying managerially controllable factors which affect software reliability. At the research site, application systems which (1) underwent frequent modification; (2) were maintained by programmers with low levels of application experience; (3) had high reliability requirements, and (4) had high levels of static complexity all showed particularly high error rates, other things being equal. It is suggested that that managers can make quantified judgements about the degree to which they wish to reduce error rates by implementing a number of procedures, including enforcing release control, assigning more experienced maintenance programmers, and establishing and enforcing complexity metric standards.