Replenishment Model Considering Supply Uncertainty for Automotive Service Parts

• Main Authors: Wei-Jung Su, 蘇韋仲
• Other Authors: 蔣明晃
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/65724756186353006159

碩士 === 國立臺灣大學 === 商學研究所 === 95 === Due to the globalization and the World Trade Organization (WTO) participating regulation, Taiwan has lowered automobile tariff year by year and also canceled the limitation of spare parts homemade rate of homebred autos. Viewing the local market, local automotive companies have suffered in dilemma of price war to protect their market shares and faced the challenge from importing cars. Without economic of scale in production, local agents have no bargaining power to suppliers; moreover, large amount of adverting and authorized expenses also erode the profitability of local agents. All of these lead automotive industry in Taiwan to a tough situation. In spite of diminishing of car selling market in Taiwan since 1994, enterprises need to develop another department to recover the lost margin in car selling. Local agents turn into after-sales service market to provide diversified service, such as repairing service, insurance, purchasing installment and auto releasing service, not just offering a premium and additional dividends to promote car selling. In order to ensure customers satisfaction to re-consume, local agents must store a fixed level of spare parts to meet customers’ emergency demand and maintain a certain service level. Too much and unnecessary inventory may keep too much current capital, resulting in difficulty of business operating. Lowering down inventory level , however, may damage the desired service level. In this paper, it is studied how to restructure a new inventory policy based on the existing inventory management methods although there are plenty of papers about the relationship of inventory level arising and stochastic demand. This study focus on discussing the stochastic of lead time of supply-side generate rising inventory under known and controllable demand variation. By taking a real local automotive agent—H Inc. as the case to discuss, this study plans to use FCM algorithm for clustering the parts most frequently demanded with large quantity. Through setting up clustering rules, the optimal reorder cycle would be calculated by the tradeoff among related inventory costs. And at last, it turns out to establish a reasonable and logical inventory policy for H Inc. used. As the results of simulations, it is found that programming model of this study can efficiently decrease current inventory quantity under certain limitation of service level. The difference between air and sea transportation expenses and the margin of service parts has mutually impact on deciding order cycle. Further via sensitive analysis, it is suggested for enterprise to lift order cycle if the less-than-cargo emergency parts transportation expenses increase or inventory carrying costs raises. Observing from the inventory model, moreover, other inventory-related opportunity cost would have great influence on inventory level for the purpose of maximizing customer satisfaction.