風險管理下供應鏈買回契約決策

Abstract

供應鏈活動中，當市場需求具不確定性時，必定存在存貨的風險。在供應商與零售商買賣關係中，零售商為避免存貨風險，使得訂購量無法真正反映市場需求，因而可能降低零售商本身、供應商以及整體供應鏈三方面利潤效率。在此背景下，產生許多不同類型供應鏈契約，如批發價契約、買回契約、盈收分享契約和訂購量契約等。在銷售季節開始前，供應商與零售商，先透過提供合適的資訊和激勵措施來訂定契約，以尋求雙方協調，增加銷售通路效率，企圖創造出零售商、供應商以及整體供應鏈三贏的局面。其中買回契約即為報童模型中，上游供應商為激勵下游零售商以提高訂購量之契約。 以往供應鏈買回契約之研究在處理市場需求不確定問題時，常以最大化期望利潤為目標，將未來市場需求量以過去市場需求量之歷史資料或是產品特性建立機率密度模型，並以統計方式得到期望利潤。若只以期望利潤為目標來考量決策，容易忽略了必須承擔的風險成本；在利潤離散程度越大時，風險成本越大，甚至造成財務槓桿失衡，對於零售商、供應商以及整體供應鏈很有可能因此面臨不可挽回的財務危機。 本研究主要課題為風險管理下供應鏈買回契約決策。嘗試以風險管理之角度，建立在供應商與零售商買賣關係下，買回契約之二階層供應鏈通用模式，並探討風險管理下決策變動之關係。在模型建構中，本研究以平均數變異數法，建立風險管理下，二階層供應鏈買回契約決策模式。並以解析法及數值法，探討決策模式在批發價、零售價固定，買回條件為「未售出完全買回」之下，訂購量及買回價的決策變動關係。然而，在不同契約決策情境及決策者風險偏好下，形成不同契約決策，本研究利用簡例代入模型中，並分別以契約決策情境與決策者風險偏好兩維度進行決策探討。

Whenever demand is uncertain, there is the risk of excess inventory in supply chain. In the trade relationship between the suppliers and the retailers, the order quantity cannot truly reflect the market demand due to the retailers want to avoid the risk of excess inventory, which may reduce the profit efficiency of retailers, suppliers and the overall supply chain. In this background, there are different kinds of supply chain contract, such as the wholesale price contracts, buyback contracts, revenue-sharing contracts, quantity-based contracts and so on. Before the selling season, the suppliers and the retailers first set contract through the provision of appropriate information and incentive policies, in order to seek the coordination, increase the efficiency of sale channels and attempt to create win-win-win situation among retailers, suppliers and the overall supply chain. The buyback contract is the newsboy model, which is the contract that suppliers encourage retailers to improve the order quantity.

In the past research, when dealing with the issue of uncertain market demand, often set the goal for maximizing the expected profit, and constructed the probability density model of the future market demand according to the history information or the product characteristic of the past market demand, and applied the statistics method to get the expected profit. If we only take the expected profit as the goal for considering the decision-making, there will easily ignore the risk cost. When the degree of dispersion in profit is greater, the risk cost is greater. Even the financial leverage may out of balance, and retailers, suppliers and the overall supply chain may face irreparable financial crisis. In this research, the major issue is the decision-making in supply chain buyback contracts with risk management. Try to construct the general two-hierarchy supply chain model of the buyback contracts from the viewpoint of risk management, and discuss the relationship between changes of decision-making. Construction of the model in this study applies mean-variance, and establishes the two-hierarchy supply chain model of the buyback contracts under the risk management. And adopts numerical and analytical method, discussing when the wholesale price and the retail price are fixed under the buyback condition that is full return, the decision-making change relationship between the order quantity and the buyback price. However, in different contract decision-making scenario and different decision-maker risk preferences, there will be different contract decision-making. This study uses the simple example into the model, and discusses the decision-making under the contract decision-making scenario and the risk preferences of decision-maker.