需求预测对零售商期望库存水平的影响分析

研究由一个供应商和一个零售商组成的简单二级供应链系统，在假定零售商面对的市场需求服从一阶自回归模型AR（1）并且零售商采取滑动平均法对未来需求进行预测的背景下，证明了如果外界输入的白噪声服从正态分布，则零售商面对的市场需求以及发出的订货量也服从正态分布，并基于此导出了零售商的期望库存水平公式，进而给出了零售商期望库存水平和系统牛鞭效应水平之间的关系方程，解释了为什么供应链系统中牛鞭效应会引起节点企业库存大量积压的现象。

Analysis of The Influence on The Bullwhip Effect of A Supply Chain and The Expected Inventory Level of The Retailer Caused by The Demand Forecasting Based on Moving Average Method

This paper studies a simple two-stage supply chain formed by a supplier and a retailer, with assuming that the market demand obeys AR （1） and the retailer forecasts the future demand with Moving Average Method, we prove that if the external importing noise obey Normal distribution, the market demand and orders the retailer sends obey Normal distribution, too, we deduce the expected inventory-level formula of the retailer based on this conclusion, the relation equation between the expected-inventory-level formula of the retailer and the Bullwhip Effect is also established at the same time, which explains the phenomenon that the Bullwhip Effect always leads to a overstocking inventory in the enterprise.