Reasoning About Device Behavior Using Qualitative Physics

A computer program has been developed which reasons about the behavior of devices using qualitative models of their structure and function. The ultimate goal of this qualitative reasoning system is to provide a general method for representing and reasoning about behavior throughout a device's life cycle. Current capabilities of the system include reasoning about the normal behavior of a device, detection of abnormal behavior, and diagnosis of failure without prior knowledge of the device's failure modes. A tool to assist in construction of hierarchical qualitative models has also been developed. Applications of qualitative reasoning under development are described.