考虑预测准确性的快时尚产品两阶段订货策略研究

Twostage Inventory Model Considering Forecast Accuracy of Online Fast Fashion Products

以销售季仅有一次补货机会的线上快时尚产品为研究对象,通过更新需求估计区间将再订货时间对需求预测准确性的影响整合到两阶段订货模型中。以两阶段利润最大化为目标确定首次订货量与再订货量,受第一阶段期末是否有存货的影响,存在第一阶段利润最大化和两阶段联合利润最大化两种确定首次订货量的策略。当第一阶段期末无存货时,第一阶段利润最大化策略更有优势。从总期望利润来看,当第一阶段的批发价格超过第二阶段批发价格一定量后,第一阶段利润最大化策略更有优势,否则,两阶段联合利润最大化策略更占优势。考虑时尚产品的需求不确定性高、第一阶段期末存货可以在第二阶段销售的现实,提出以第一阶段成本最小化和最大化满足第一阶段需求为目标确定首次订货量的订货策略。考虑到不同订货策略的优劣受再订货时间的影响,给出了基于实际利润选择最优订货策略的步骤。实验发现,与单阶段库存模型和不考虑需求预测准确性动态变化的线下快时尚产品的两阶段订货策略相比,考虑需求预测准确性的两阶段订货模型的利润分别提升76%和300%以上。一般情况下,采用两阶段联合利润最大化的订货策略更具有优势,但当预测精度较低时,应采用更保守策略的确定首次订货量。

Retailors of short lifecycle products,such as fashion goods,have a single replenishment opportunity during the sales season.The initial order quantity,replenishing time and quantity are three interrelated decisions.The improvement of forecast is time-dependent because of the observed demand information increasing with time.The time-dependent improvement of forecast is integrated into a two-stage inventory model by adjusting the range of estimated demand interval in the second stage.Four order policies(PMNI:the profit maximization assuming no inventory left at the end of the first stage,PMSI:the profit maximization assuming some inventory left at the end of the first stage,CM:the cost minimization of the first stage,and MD:meet the demand of the first stage in maximum degree)are proposed to determine the initial order quantity and illustrate the process to find the best one.PMNI is the best choice among the four policies when there is no inventory left over at the end of the first stage.As for the total expect profit of the two stage,if the whole sales price of the first stage is more than that of the second stage to a certain value,PMNI is dominant than PMSI,otherwise,vice versa.Handu,which is a typical fast fashion E-commerce enterprise in China,is selected to illustrate how to choose the best ordering policy based on the actual total profit.The empirical data analysis illustrates the profit in case of the two-stage inventory model considering forecast accuracy will improve 76%than that in case of single-stage inventory model,and 300%more than that in case of the two-stage inventory model for offline fast fashion products without considering the dynamic changes of forecast accuracy(Fisher et al,2001);in general,MPSI will be dominant comparing with MPNI.If the range of forecast demand interval is large,the conservative ordering policy,like MPNI and MC will get more profit,especially the cost of overstock is more than the cost of lost-sale.The way of integrating the forecast accuracy into the inventory model to decide the replenishing time will inspire the research on time decision of other inventory model in different cases.The analytic findings and empirical observation will help the retailor to choose the best ordering policy to get more profit.