A Case-Based Reasoning System using Case Evaluation for Diagnosis Tasks

Abstract

This paper describes a case-based reasoning system using case evaluation for diagnosis tasks(called CBED). The knowledge is based on a cost expectation value which is calculated from objective and subjective values. We have been developed the quality management system, which employs a stochastic method. However, in some cases, this stochastic-based system doesn't select good cases. Therefore, we integrated some expectation values into the case selection mechanism. The CBED has some expectation measurement. Its case selection criteria use not only similarity, but also some expected values. Some unforeseen malfunctions may occur due to unsuitable design, manufacturing condition and unsuitable usage. The similarity is not enough to select useful cases from a case base. Because the similarity is based on the product models. The CBED adopts the cost effective expectation value to pick up cases. The CBED selects important repair cases based on the quality of cases, which considers repair time, repair part cost, trouble recurrence, the accuracy of reasoned cause and maintenance difficulty. We validated this system in real product repair problems.