傳統的重複性訂購作業模式通常均假設每次的訂購成本為固定常數,因此訂購成本與總成本成簡單的線性函數關係,事實上,在訂購作業的過程中,由於受到學習效果的影響,每單位的訂購成本不應是固定的常數,且由於訂購作業的中斷會引發遺忘效應,使得系統的實際總成本應高於僅考慮學習效果的總成本。本研究主要在可控前置時間之連續盤查存貨系統及具有欠撥價格折扣和部份銷售損失之混合存貨模型探討學習效果與遺忘效應對訂購成本的影響,其中訂購量、欠撥折扣、安全因子及前置時間均為決策變數,目標使期望總成本為最小。在此,本研究假設前置時間內需求量的機率分配一個為常態分配而另一個為一般分配情形。本研究亦提供演算法分別求得最佳訂購量、最佳欠撥折扣、最佳安全因子以及最佳前置時間,此外,並利用數值範例說明結果。
Traditionally, the pattern of repeated ordering process is assumed that ordering cost is always constant, hence the relationship of ordering cost and total cost can be simple linear function. In fact, each unit of ordering cost can not be fixed constant due to learning effect in the process of ordering operation. Moreover, the interruption of ordering operation will cause forgetting effect, and results in the actual total cost higher than the total cost which only takes learning effect into consideration. This paper investigates the impact of learning effect and forgetting effect on ordering cost for the continuous review inventory model involving controllable lead time with the mixture of backorder price discounts and partial lost sales. In the circumstance, order quantity, backorder price discount, safety factor and lead time are decision variables. The objective is to minimize the expected total cost with respect to related decision variables. We assume that probability distributions of the lead time demand are one for the normal distribution and another for the general distribution. We also develop an algorithm procedure, respectively, to find the optimal order quantity, optimal backorder price discount, optimal safety factor and optimal lead time. Furthermore, two numerical examples are also given to illustrate the results.