Decision Of Condition-based Maintenance And Joint Decision Of Maintenance And Spare Parts Inventory For Standby Repairable System

The standby repairable system is widely used in industry and is a relatively important system.The standby repairable system such as mine ventilators and steel rolling systems,the equipment in the system has the characteristics of periodical alternate use,the failure characteristics of the system are determined by the performance and degradation characteristics of all the alternate use equipment,and the equipment in this type of system can usually be reused after multiple maintenance.The maintenance strategy of this type of standby repairable system is complicated,so the research on decision of maintenance needs to be specially carried out in this system.The smooth implementation of the maintenance activities of the standby repairable system is restricted by the spare parts inventory,and there is a strong coupling relationship between maintenance and spare parts inventory.Therefore,it is necessary to find a balance point between maintenance and spare parts inventory management.Only by finding a balance point between maintenance and spare parts inventory management can the optimal strategy be obtained.This paper studies the research on decision of condition-based maintenance and joint decision of condition-based maintenance and spare parts inventory through modeling and optimization for standby repairable system that requires periodic switch or replace of equipment.The main research contents are as follows:(1)The decision of periodic-switching offline condition-based maintenance for single-standby repairable system.For single-standby repairable system,a periodic-switching off-line condition-based maintenance strategy is formulated,a maintenance decision model is established,a maintenance degree model is established,the calculation model of the steady-state probability density function of the system is derived,the optimal maintenance strategy is solved.Numerical experiments are carried out to verify the research by taking the mine ventilators as a case,and research results show that the decision-making model established based on the switching offline condition-based maintenance strategy can effectively reduce the system maintenance cost rate.(2)The decision of periodic group replacement condition-based maintenance for multi-standby repairable system.For multi-standby repairable system which is composed of multiple identical and independent components,a periodic group replacement condition-based maintenance strategy is formulated,a maintenance decision model is established,the result is optimized through genetic algorithm.The research is verified through experiments by taking the steel rolling system as a case,and research results show that the maintenance plan of multi-standby repairable system should adopt a moderate cycle to replace and inspect the system,and a moderate preventive maintenance threshold and a high maintenance degree should be adopted to carry out preventive maintenance activities.(3)The joint decision of group replacement condition-based maintenance and spare parts inventory for multi-standby repairable system.Considering the impact of spare parts ordering,a joint strategy of condition-based maintenance and spare parts ordering is proposed for multi-standby repairable system which is composed of multiple identical and independent components,a joint decisionmaking model is established,the inventory status probability is derived,and the optimal joint strategy is solved.The research is verified through experiments by taking the steel rolling system as a case,and research results show that the more complex the composition of the standby repairable system in the joint decisionmaking process,the higher requirements for system security,and the higher the safe inventory level and maximum inventory level are.