INVESTIGATING THE APPLICABILITY OF PETRI NETS FOR RULE-BASED SYSTEM VERIFICATION

As rule-based system (RBS) technology gains wider acceptance, the need to create and maintain large knowledge bases will assume greater importance. Demonstrating a rule base to be free from error remains one of the obstacles to the adoption of this technology. Traditional approaches to RBS verification have generally involved pairwise comparison of rules, making them inefficient for large systems with chained errors. The paper presents an alternative approach to RBS verification, wherein the system is modeled as a Petri net and error detection performed therein. A set of propositions is formulated to locate errors of redundancy, conflict, circularity, and gaps in domain knowledge. Rigorous proofs of these propositions are provided. Difficulties in implementing a Petri net-based verifier are discussed, as well as potential restrictions of the applicability of this approach.