k/N（G）结构系统初始备件配置方法

针对现有备件冗余度建模中无限呼叫总体假设不合理、供应可用度计算困难的问题，提出一种k/N（G）结构系统初始备件配置方法。首先，采用有限源排队论获取备件短缺数概率分布。然后，给出计算k/N（G）结构系统供应可用度的方案，并证明了方案的正确性。该方案在计算随机挑选的一套系统未因备件短缺而停机的概率基础上，利用k（或更多）套系统良好的二项分布概率估计系统供应可用度。最后，应用边际分析算法确定各项备件的数量。实例分析表明：该方法能优化k/N（G）结构系统各组成部件的库存数量，且与单项法相比具有明显的优势，能以较少的备件费用达到相同的供应可用度目标。

Initial Spare Allocation Method for k/N(G) Structure System

There are two problems in traditional spare part redundancy model. One is the illogical use of infinite calling population assumption. The other is the difficulty in computing system supply availability. In order to solve these problems, an initial spare allocation method for k/N(G) structure system is presented in this paper. Firstly, the finite source queuing theory is used to obtain backorders distribution probability of spare parts. Secondly, a scheme is established to compute the k/N(G) structure system supply availability. Rationality of the proposed scheme is proved. Probability of a randomly chosen system will not be down due to spare parts backorders being estimated, and the whole k/N(G) structure system supply availability is approximated by the binomial distribution probability that k or more systems are mission capable. Finally, the marginal analysis method is used to optimize spare parts inventory in the k/N(G) structure system. Examples show that compared to the single item method, the proposed method can achieve the same supply availability target by paying less money.