A Study of Inventory Control for a Supply Chain with Variable Lead Time and Service Level Constraints

• Main Authors: I-Hung Hsieh, 謝依宏
• Other Authors: Shu-Lu Hsu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/97482820443478275168

碩士 === 國立嘉義大學 === 行銷與流通管理研究所 === 93 === With the increasing competition in market, businesses usually hold large stocks in order to satisfy required service levels of customers. About control and management of inventory system, lead time is one of the important factors which may influence strategies. In fact, a company can reduce safety stock as well as increase service level via shortening the lead time of inventory replenishment. The lead time is composed of times of several operations among trading parties, such as ordering, manufacturing, delivering, and storing. Therefore, the reduction of lead time may involve with all trading parties to improve the related operations. However, most of earlier research has considered this issue as a single buyer’s decision. This thesis is to study the effect of lead time reduction on the inventory decisions for a single supplier and multiple buyers supply chain under stochastic demand and constraint service level. The study initially focuses on a supply chain consisting of a single supplier and its multiple buyers with probabilistic demand following a normal distribution. The vendor is assumed to adopt an outbound freight consolidation policy and thus merchandises to each buyer on a common cycle. A common-cycle periodic review inventory model is proposed to determine the optimal common cycle and target levels for replenishments of all trading parties. The models revise the work of Banerjee & Banerjee (1994) by incorporating the ordering cost and a stricter solution procedures under two common service level constraints. Besides, two of the models extends the proceeding common-cycle inventory model by involving variable lead time with extra crashing cost. The optimal lead time, the common cycle and the target levels for replenishments are derived under two common service level constraints, and the application of model is further illustrated by a stair-step lead-time reduction cost function. Numerical experiments and sensitivity analyses are also performed for the stair-step lead-time reduction cost case, which give managerial implications of effects of parameters on the total system cost.