Structural testing of rule-based expert systems

Testing of rule-based expert systems has become a high priority for many organizations as the use of such systems proliferates. Traditional software teting techniques apply to some components of rule-based systems, e.g., the inference engine. However, to structurally test the rule base component requires new techniques or adaptations of existing ones. This paper describes one such adaptation: an extension of data flow path selection in which a graphical representation of a rule base is defined and evaluated. This graphical form, called a logical path graph, captures logical paths through a rule base. These logical paths create precisely the abstractions needed in the testing process. An algorithm for the construction of logical path graphs are analyzed.