Conversion of a rule based to an object oriented expert system

The conversion of the NETHELP system from a rule-based system to an object-oriented system is described. Specifically, conversion was from the rule-based system written using Teknowledge´s M.1 expert System Shell to the Object Oriented Nexpert Object Tool. The conversion progressed from a straightforward one-for-one conversion to a systematized use of the object and class mechanisms. The straightforward conversion became unwieldy from several points of view. There was no straight conversion of multivalued variables, and the use of forward chaining would not work properly with the modular nature of the knowledge bases. A diagnostic model was developed that made use of many of the features of the Nexpert Object Tool. After this model was developed, it became apparent that it could be used to diagnose any equipment on the Federal Express SNA Network. The model has been used since in all the modules developed for the system with the advantage that once the maintenance workers become familiar with the model, maintenance of any of the knowledge bases will be familiar to them