Reflection on the implementation of a software design

On a recent software development project the develop ment group elected to ernploy the Nassi-Shneiderman' chart for design specification, formal structured walk through, assembly coding, and peer code review. A review of the statistics of the code change suggests that personnel turn-over and the level of design refine ment have significant effect on the correctness of the program code. In addition, a new symbol is suggested for the Nassi-Shneiderman flow diagram to specify Mutual Exclusion.