Developing error-free software

The authors describe experience gained in designing reconfiguration-error-free software at IBM's Federal Systems Division in Houston. From 1982-5, this division reduced software product defects to 0.11 errors per thousand lines of source code. Four measurements defining software quality are described. Also discussed is NASA's development of a standardized software support environment, and the US Department of Defense Software Technology for Adaptive Reliable Systems (STARS) program. These environments provide for early control, standardization, and integration of requirements, leading to more easily maintained software and reduction of critical skill level for its maintenance.<<ETX>>