Proactive maintenance scheduling in consideration of imperfect repairs and production wait time

Abstract

Abstract Wait time due to the exhaustion of raw materials or lack of demand is common in manufacturing/production processes, which provides cost-effective maintenance opportunities. This paper designs a two-phase opportunistic maintenance framework based on defect information, which integrates properties of production waits into the decision-making process. At the first phase, a finite number of inspections are executed to reveal the defective state, followed by imperfect preventive repair. At the second phase, no maintenance action is taken until reaching a scheduled maintenance window (postponed maintenance) or arrivals of production waits (opportunistic maintenance). The integration of imperfect repair with postponed and opportunistic maintenance enables a sufficient utilization of remaining useful lifetime and a flexible resource allocation. Under the constraint of the steady-availability requirement, the optimal policy minimizing the system maintenance cost is obtained via the genetic algorithm. A case study from a steel convertor plant shows that our policy outperforms some classic maintenance policies.