AbstractAny system can be defined in terms of structure, operation, and decision making. If one is to compare system design structures and operations accurately, an optimal set of decision rules is required for each alternative, development of which can be very difficult. The Operational Evaluation Modeling (OpEM) inductive/adaptive expert system controller can greatly facilitate this task. The decision rule development procedure optimizes system effectiveness by initial induction of the rule tree, using sample decision cases, followed by adaptive rule modification, using a run time simulation program interface and automatic rule strength modification. The rule specification language consists of all primitives needed to implement local and global reasoning. These primitives include fuzzy facts (object-value couplets) and variable instantiation of facts. Rule development interlace capabilities include manual optimization of fuzzy object set function variables and addition or deletion of rules.