本文針對變動前置時間，機率性需求且服從常態分配，允許缺貨且進貨價格具數 量折扣之情況下，建構一存貨數量模型，透過最佳化技術及電腦數值分析方法，尋找最適之 訂購量及安全存量水準，以使總存貨成本最低。關於變動前置時間之設定乃依Kim及 Benton[10]所提出之概念加以引申而得，亦即前置時間為訂購量之線性函數關係。本文所建 構之存貨模型因具多重變異性，因此必須藉助電腦數值分析方法，方能找到符合要求之最適 解。最後本文提出若干具體之發現與結論。

　　　　　This paper proposed an inventory mathematical model to search for the optimal lot size and safety stock level under the following situations: variable lead time, random demands with normal distribution, permitting stockouts and purchasing price with quantity discount. For solving this problem, the paper applied two mathematical techniques the optimization technique and computerize numerical analysis method. For variable lead time, this paper followed the idea that Kim and Benton proposed setting the lead time to be a linear function of lot size. Because the model we developed has multi-variation, so we applied the computerize numerical analysis method to search for the optimal solution. Finally, this paper proposed several concrete findings and conclusions.