Summary: | 博士 === 國立交通大學 === 經營管理研究所 === 89 === Efficient customer service is essential to the supplier as it affects the sales directly. As to the spare parts supply chain in the semiconductor equipment industry, inventory control of spare parts is one of the most important activities for the supplier in Taiwan. Due to the following complex nature of semiconductor manufacturing: machines are upgraded rapidly; they have high precision and many kinds of spare part requirements; one machine can contain hundreds or thousands of different parts; large differences in unit cost and varying demand rate of spare parts in semiconductor equipment; the design and evaluation of spare parts inventory system for local supplier becomes an important issue.
This paper aims to establish inventory models for spare pats of the semiconductor equipment. In model I, we focus on the case of spare parts with high cost and low usage. Using varying lead times and machine life cycles, a simple method to evaluate the relationship between inventory level and service level is developed. In model II, we focus on the spare parts in high usage of semiconductor equipment. The same as model I, we evaluate the stock level for given service level. In model III, we discuss the cost structure of inventory cost for the spare parts in high usage. Demand for spare parts can be classified into critical and non-critical demand, depending on the criticality of the equipment for production process. To effectively handle this situation in spare parts inventory control, we propose a stocking policy based on the stochastic continuously reviewed fixed reorder quantity policy (Q, r), where some of the stock is reserved for critical demand.
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