在現今的零售市場中存在一個有趣的現象，即期品零售商購買一般零售商即將到期的商品並重新銷售給消費者，此現象往往導致更好的市場區隔並增加消費者和零售商的效用。本研究針對一般零售商和即期品零售商之間的競合，建立 EOQ模型，並比較分散式和集中式控制（決策）對於利潤的影響。同時，為了精準描述商品的需求，本研究模型提出一個基於價格、商品效期、展示量的多變量需求函數，同時也放寬了常用之零期末庫存假設。本研究考慮商品價格、期末庫存和庫存循環時間三個主要決策變數，另外當一般零售商可考量降價方案時，加入降價額度與降價後的庫存量兩個決策變數。研究結果顯示建立一般零售商和即期品零售商之間的關係可增加零售商的利潤，而當中又以分散式控制決策下，一般零售商同時考量降價選項的方案會促成最高的利潤。雖然一般零售商和即期品零售商的利潤之間呈反向關係而互有消長，但整體而言，集中式決策會為兩種零售商帶來更高的市場滿意度。此外，若需求函數是依商品新鮮程度遞減的凸函數，增加上游供應商供給商品的前置時間將顯著降低一般零售商的利潤。

A unique phenomenon in the retailer market nowadays, where some of the retailers (salvage retailers) buy nearly expired grocery products from other retailers and resell them, may lead to the better market segmentation and increase the utilities of both consumers and retailers. This study aims to model the possible relationship (i.e., decentralized and centralized controls) between the retailers and salvage retailers. To model such relationship, new demand function was developed in this study. In particular, EOQ model with demand as a multivariate function of product price, freshness, and displayed inventory level was used. Zero ending inventory assumption inventory was also relaxed to boost the sale and profit based on the demand formulation. Three major decision variables (i.e., product price, ending inventory level, and inventory cycle time) and two supplementary decision variables (i.e., markdown and amount of inventory at which markdown is applied) for markdown cases were employed in order to maximize the total profit. Results show that building relationship with the salvage retailer will generally increase the retailer’s profit and the decentralized control with markdown model gives the highest profit. Although there is always a trade-off between retailer and salvage retailer profits, overall, the centralized control leads higher market satisfaction on both sides. In addition, we also find that under convex decrease freshness elasticity function, an increasing in time to supply will reduce the retailer’s profit significantly.

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