Abstract: Task-oriented production equipment often faces mixed load working conditions of normal load and over load.Making more scientific and reasonable decisions on equipment maintenance and spare parts inventory optimization can better grasp the operating status of equipment.To study the degradation of equipment under mixed load,a hybrid degradation model of multi-component system composed of key components and non-critical components under mixed load was established,and the spare parts inventory strategy of different components and the probability expression set of parts maintenance demand,spare parts arrival on time and inventory state were proposed.The judgment conditions of the conversion between preventive maintenance and preventive replacement were constructed.The detection interval,the minimum safety inventory of non-critical components,the preventive maintenance threshold and the order threshold were all taken as optimization objectives,and the joint optimization model of equipment on-demand maintenance and spare parts inventory was established.The effectiveness of the joint optimization model was verified by MATLAB.Compared with the model only considering normal load,the maintenance cost under mixed load was significantly different from that under normal load,suggesting that enterprises could not ignore the influence of slow and continuous accelerated degradation of equipment under excessive load on maintenance activities and inventory ordering in actual production.

Key words: multi-component system, mixed load, maintenance according to the situation, spare parts inventory

摘要： 以生产任务为导向的任务型生产设备经常面临正常负载和超负载的混合负载工作情况,为了准确掌握设备运行状况,进行科学合理地设备维修与备件库存优化决策,针对混合负载下设备的退化状态研究了混合负载下的设备不同退化状态以及维修和备件库存决策,建立了由关键部件与非关键部件组成多部件系统的混合退化模型,并提出不同部件的备件库存策略和部件维修需求、备件到达时间、库存状态的概率表达集;构建了预防性维修与预防性更换转换的判断条件,并将检测间隔时间、非关键部件最小安全库存、预防性维护阈值和订购阈值同时作为优化目标,建立设备视情维修与备件库存联合优化模型。采用MATLAB验证了联合优化模型的有效性,与仅考虑正常负载的模型比较,混合负载下的维修费用与正常负载下的维修费用有明显差异,提示企业在实际生产中不能忽略超负载下设备加速退化对维修活动与库存订购的影响。

关键词: 多部件系统, 混合负载, 视情维修, 备件库存