考虑不完全维修的民机可修件多级库存规划

Multi-Echelon Inventory Allocation under Imperfect Repair for Repairable Spares of Civil Aircraft

针对现有的备件库存优化模型无法准确描述民机可修件由于不能修复如新导致其性能逐次劣化及一定维修次数后报废的实际情况,结合准更新理论、排队论和Vari-Metric模型提出了考虑不完全维修的民机可修件多级库存规划方法。以准更新理论模拟劣化过程,得到可修件的报废量;考虑维修后工作时间逐次缩短和维修时间逐次增加,调整了M/M/c/m+S/m排队论模型,得到了可修件的需求量;在此基础上提出引入报废流,针对可修件的报废决策问题扩展了Vari-Metric模型,以最小化备件投资费用为目标,采用边际分析法对模型进行求解并得到可修件库存配置方案。通过算例分析,表明所提方法能够考虑不完全维修情况下为民机全寿命阶段的多级备件保障决策提供有效参考。

Because the repairable spares of civil aircraft after repair are not as good as new, and therefore causes performance deterioration progressively and scrapped after a certain number of maintenance, which current spare parts inventory optimization models cannot describe it accurately. Focus on this problem, this paper proposes the multi-echelon inventory allocation method under imperfect repair combined with quasi renewal theory, queuing the- ory and Vari-Metric model. At first, simulate of deterioration process based on quasi renewal theory and get the a- mount of scrap. Then, considering the working hours after maintenance is shortened and the maintenance time in- creased gradually, the M/M/c/m＋S/m queuing theory model is adjusted to g-：t the d. -l,,M of repairable spares. On this basis, this paper introduces scrap stream and extends Vari-Metric model for the obsolescence of spare parts. Af- terwards, obtaining biggest economic benefits with minimal investment costs is selected as objective, marginal analysis method is set as the optimization to solve the model and get the allocation scheme of repairable spares. Through the example analysis, the result shows the proposed method can provide effective reference for the spare parts sup- port decision of civil aircraft＇s total life-span cycle.