A New Programming Methodology for Long-Lived Software Systems

A new software development methodology based on the language NIL is presented. The methodology emphasizes (1) the separation of program development into functional specification and tuning phases, (2) the use of a fully compilable and executable design, (3) an interface definition and verification mechanism. This approach reduces life-cycle costs and improves software quality because (a) errors are detected earlier, and (b) a single functional design can be re-used to produce many implementations.