Guidelines for the verification and validation of expert system software and conventional software: Survey and documentation of expert system verification and validation methodologies. Volume 3

This report is the third volume in the final report for the Expert System Verification and Validation (V ampersand V) project which was jointly sponsored by the Nuclear Regulatory Commission and the Electric Power Research Institute. The ultimate objective is the formulation of guidelines for the V ampersand V of expert systems for use in nuclear power applications. The purpose of this activity was to survey and document techniques presently in use for expert system V ampersand V. The survey effort included an extensive telephone interviewing program, site visits, and a thorough bibliographic search and compilation. The major finding was that V ampersand V of expert systems is not nearly as established or prevalent as V ampersand V of conventional software systems. When V ampersand V was used for expert systems, it was almost always at the system validation stage after full implementation and integration usually employing the non-systematic dynamic method of open-quotes ad hoc testing.close quotes There were few examples of employing V ampersand V in the early phases of development and only weak sporadic mention of the possibilities in the literature. There is, however, a very active research area concerning the development of methods and tools to detect problems with, particularly, rule-based expert systems. Four such static-testing methods were identified which were not discovered in a comprehensive review of conventional V ampersand V methods in an earlier task