Research on periodic preventive maintenance strategy for discrete production system considering unexpected failure risks

Preventive maintenance strategies guarantee the dependable functioning of discrete production systems, albeit at a considerable financial expense for enterprises. To tackle the challenge of managing operational and maintenance costs in these systems, this study introduces a failure model grounded in the hybrid failure rate. This model integrates both an age-reduction factor and a failure rate increment factor, allowing for a versatile depiction of failure patterns across diverse equipment types. A key innovation of this study is the explicit incorporation of risk costs arising from unexpected failures into the maintenance cost model, which are often neglected in conventional strategies. Leveraging the proposed failure model, we have formulated a periodic maintenance cost model tailored for discrete production systems. This model encompasses maintenance costs, downtime losses, as well as the potential risks associated with unanticipated failures. By refining the frequency and timing of intermediate repairs within the maintenance strategy, this study offers a scientifically grounded maintenance plan for discrete production systems. Case study findings reveal that, when compared to existing strategies, the proposed maintenance strategy, which accounts for the risks of unexpected failures, achieves a reduction in total maintenance costs by 20.19% and 7.85%, respectively. This preventive maintenance strategy not only bolsters economic efficiency and reliability but also serves as a robust foundation for developing scientific maintenance schedules for equipment in discrete production systems.