Abstract: This paper is focused on improving supplier’s service level in VMI system. We present a delivery scheduling problem to minimize the stock-out losses, when the retailers face a periodical demand and the supplier adopts direct delivery strategy. Considering the characteristic of retailers’ demand intervals, we design RTE strategy. For three different kinds of loss rates of stock out in reality (marginal loss rate, fixed loss rate, and increasing loss rate), we prove the approximation ratios of RTE strategy in different conditions respectively. After analyzing the approximation ratios and two computational examples, we find RTE strategy performs best for marginal loss rate, and even it can be an optimal stragety in some cases. The results are of significance to supplier’s delivery scheduling for a periodical demand.

Key words: logistics delivery, scheduling, approximation algorithm, periodical demand

摘要： 在供应商管理库存(VMI)模式中,从提高供应商服务水平的视角,研究零售商具有周期性需求,供应商采用直接配送策略情形下以最小化缺货损失为目标的供应商配送日程安排问题。根据零售商最大需求周期的特点,设计了R倍放大(RTE)策略,分别针对实际中的边际缺货损失费率、固定缺货损失费率和递增缺货损失费率,证明了RTE策略在配送周期满足不同条件下对应的近似比。通过近似比的比较和算例分析,发现RTE策略在边际缺货损失费率下表现最好,某些情形下可以达到最优。研究结果对面对周期性需求的供应商配送排程具有一定的指导意义。

关键词: 物流配送, 排程, 近似算法, 周期性需求