Operational risk-based opportunistic maintenance approach for multi-station manufacturing systems considering machine performance–workpiece quality co-effect

Opportunistic Maintenance (OM) refers to a type of maintenance activities implemented in machine idle times during the system operation period. For manufacturing systems, the objective of OM policy optimization is to minimize maintenance costs and losses while reducing the operational risk of manufacturing systems. However, the machine performance–workpiece quality co-effect (M–W co-effect) has not received sufficient attention in existing studies on risk-based maintenance (RBM), resulting in the inability to accurately qualify and control operational risk. Therefore, a risk-based opportunistic maintenance approach for the multi-station manufacturing systems that considers the M–W co-effect is proposed. First, the causality analysis method is used to expound the M–W co-effect that exhibits the bidirectional coupling relationship between workpiece quality deviation and machine performance degradation. Second, based on the proposed M–W co-effect, the operational risk of multi-station manufacturing systems is quantified in terms of physical and functional failures, where the functional failure risks include explicit and implicit risk. Third, based on the operational risk quantification result, a novel opportunistic maintenance decision-making model is established. Finally, the feasibility and correctness of the approach are verified through a seal manufacturing system.