NOSES object-oriented switching software in C++-non-stop service enhanceable software

NOSES (non-stop service enhanceable software) has been developed applying techniques for realizing high reliability and a low cost by increasing the extent of software reusability. The paper describes these design techniques, in particular those involving the use of the C++ language. The reliability techniques described are call-recovering restart, call-recovering executing file-update, and on-line partial file modification. Software reusability is increased by using customizable platform software. In evaluating these techniques, the resulting increase in the number of instructions per call is estimated, and a method is proposed for measuring the increase in software reusability in an object-oriented design environment