供應鏈中的水平競合模式與通路垂直關係之研究

Modeling the horizontal competition / cooperation and the vertical relationship in the supply chain

王志軒(Chih-Hsuan Wang)

指導教授 ： 郭瑞祥 ； 蔣明晃

國立臺灣大學/管理學院/商學研究所/博士(2005年)

https://doi.org/10.6342/NTU.2005.00134

摘要

本論文可分成兩大主題：第一主題是探討在雙佔結構下，兩家上游的製造商爭取下游零售商之訂單時，彼此間的水平競爭或合作關係；其中，品質與上游價格為製造商的決策變數，而零售商的決策變數僅為下游價格。假設製造商第一期的品質投資會透過品質成本控制因子而產生品質成本，但其亦可以產生品質效益；再透過生產成本介入因子進而降低製造商第二期之生產成本。研究結果發現，若品質效益太低時，競爭性情境下的製造商並無意願來降低其品質成本控制因子，然而合作性情境下的製造商仍有誘因來降低其品質成本綜效因子；且競爭性情境下製造商的邊際利益恆小於零售商的邊際利益，但合作性情境下製造商的邊際利益恆等於零售商的邊際利益。另外，在競爭性情境之品質水準等於合作性情境之品質水準的前提下，製造商較偏愛合作性情境，而零售商及消費者則較偏好競爭性情境，且消費者在合作性情境下因享有較低的零售價格進而產生較大的產品需求。論文之第二主題則是探討供應商與採購商彼此間的上下游垂直關係，並分成品質檢測與聯合生產兩種模式。在品質檢測模式中，採購商並不進行任何加工作業，僅依據品質檢測的結果要求供應商對不良品進行維修替換或共同分攤不良品之相關成本；在聯合生產模式下，上游的供應商負責提供元件給下游的採購商進行組裝，雙方依造既定契約各自分攤不良品之失誤成本或分享產品之共同銷售利潤。不論在品質檢測及聯合生產模式中，本文均針對上下游雙方的決策模式，分別在最佳化、次佳化、供應商主導、採購商主導四種情況下進行分析比較。研究結果發現，次佳化時供應鏈成員的自利行為會使生產水準低於社會最適投資水準，但會使監督水準則高於社會最適投資水準。且在品質檢測模式中，不論是供應商或採購商均偏好供應商主導的情境，故可形成供應商-領導者與採購商-跟隨者之穩定通路均衡；但在聯合生產模式中，不論是供應商或採購商均偏好由對方當領導者、自己當跟隨者的情境，所以通路中同時存在純策略均衡及混合策略均衡。

關鍵字

供應鏈 ； 品質競爭 ； 品質檢測 ； 聯合生產

並列摘要

This thesis can be separated into two parts: first topic discusses a scenario that two upstream manufacturers are assumed to compete for the order simultaneously on price and quality or they may agree to cooperate on quality and simply compete on price. In addition, we assume that the investment of manufacturers on quality improvement in the first period can generate benefit to lower manufacturers’ production costs in the second period. Results show that competitive manufacturers may be reluctant to improve their quality cost but cooperative manufacturers may have an incentive to improve their quality synergy when the effect of quality benefit is large enough. Secondly, results show that the margin of competitive manufacturers is always less than the retailer’s, but the margin of cooperative manufacturers will be improved to be the same as the retailer’s. Under a special condition, the retailer has higher profits in the competition scenario while symmetric manufacturers have higher profits in the cooperation scenario. The managerial implication is that two manufactures facing a single retailer should cooperate with each other and enhance their quality level to reach a win-win situation, especially when the epoch of micro-profit is coming.
The second topic, using the concept of Stackelberg game, analyzes the traditional issues of quality inspection and joint production, and discusses the impact of sequential decision on supply chain management. In quality inspection, we assume that the upstream supplier incurs production cost for its yield rate and the downstream buyer incurs appraisal cost for its inspection rate. Moreover, the buyer will require the supplier to replace defective products or share relevant cost in customer service. In joint production, we assume that the upstream supplier provides internal components to be installed in their final products for the downstream buyer and both of them agree to share common sale benefit or respective failure cost according to their contract in advance. In particular, we utilize the concept of sequential decision to compare the results of decision variables and profits of channel partners among four scenarios, such as first best, second best, supplier Stackelberg, and buyer Stackelberg. Our results show that the suboptimal production level under second best is lower than the socially optimal level under first best, but the suboptimal monitoring level under second best is higher than the socially optimal level under first best. In addition, both channel members under quality inspection prefer to the scenario of supplier Stackelberg and it implies that the structure of supplier-leader with buyer-follower can sustain a stable Nash equilibrium in the supply chain. Furthermore, based on the pay-off matrix, we also show that both channel partners under joint production prefer to become followers. Hence, there are two pure strategy equilibriums and one mixed strategy equilibrium coexisting in the supply chain.

並列關鍵字

supply chain ； quality cmpetition ； quality inspection ； joint production

參考文獻

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