Stopping time optimisation in condition monitoring

Automated condition monitoring of active components of a system can improve the cost-ef®ciency of preventive and corrective maintenance and the availability of the production system. The validity, reliability and correct interpretation of the signals obtained from the condition monitoring instrumentation is important for the realisation of the potential bene®ts. The utilisation of experts in the interpretation of the condition monitoring signals is therefore crucial. In the paper, a stopping time model is formulated, where experts' judgements on the remaining operating time of a component, given an indication of incipient failure, are utilised to arrive at optimal operational maintenance decisions. Optimality is de®ned in the sense of maximising expected utility. An expert model is also formulated, which utilises percentile information elicited from the experts. The modelling framework allows for the testing of different modelling assumptions which affect the decision outcomes. q 2002 Elsevier Science Ltd. All rights reserved.