多级可修备件库存的生灭过程建模与优化

针对VARI-METRIC模型在低可用度下结果不准确的问题,建立基于生灭过程的任意等级、任意层级可修件库存优化模型。通过对各级站点、各类备件需求率与到达率的预测,对每个部件建立其生灭过程模型,并提出基于生灭过程的装备可用度计算方法。以整个保障系统的装备可用度为约束指标,以备件总购置费最低为目标,利用边际算法得到最优备件配置方案,并建立仿真模型对所得优化方案进行评估与调整。结合算例,以仿真结果作为检验标准,选取权威的VMETRIC软件与该解析模型在优化性能、计算精度及适用性上进行对比和说明。结果表明,无论是解析模型还是VMETRIC软件,均存在一定的适用范围,而采用解析与仿真相结合的方法无疑具有更强的适应性。

Modeling and optimization of multi-echelon inventory for repairable spares based on birth and death process

For the problem of long-term planning of spare parts in the whole life cycle of the equipment, the model of inventory optimization for multi-echelon multi-indenture repairable spares is built. Firstly, the birth and death process of each component are established by the prediction of demand rate and arrival rate of each spares in each sites; Then, computational method of availability is put forward based on birth and death process; With constrains of availability and objective of lowest cost, the optimal inventory distribution result is obtained by marginal algorithm and the simulation model is built to evaluate and adjust the result. In actual example, the analytic model and VMETRIC are compared and described in aspects of optimization performance, calculation precision and applicability by simulation verification, the results show that both analytic model and VMETRIC have certain scope of applicability and the method combined analytic model and simulation has stronger applicability.