| 摘要: | 在競爭激烈的商場中，可透過供應商和零售商的合作，提升企業的整體競爭力，並有效地增加利潤和降低成本。由於生產過程不完善、機器設備老舊或運送過程之人為疏忽等，將導致零售商收到的貨品中含有不良品。若零售商誤將不良品銷售給消費者，將引起消費者的抱怨、退貨、甚至不再上門購買。所以，對零售商來說，貨品中含有不良品是一項嚴重的問題。另一方面，供應商可藉由提供延遲付款的優惠來吸引零售商訂購較多的數量，即所謂信用交易。在延遲付款期間，零售商收到貨品時不需立即付現，也不用支付利息，並可以利用此期間的銷貨收入賺取利息。當付款期限結束時，若零售商仍有貨品尚未出售，則需負擔庫存貨品的資金積壓成本。另一方面，供應商因延遲收到貨款而產生機會損失成本。
本研究探討兩個存貨模式，第二章建立含有不良品的整合存貨模式，其中供應商和零售商皆提供延遲付款優惠，且需求率與零售商提供的延遲付款期間長度有關。第三章則討論當零售商訂購至某一水準時，供應商才提供延遲付款優惠，且零售商收到的貨品中含有不良品的整合存貨模式。兩個存貨模式皆以單位時間總利潤最大為目標，並各自發展出演算法以利求解。最後以數值範例說明求解過程並做敏感度分析，以瞭解參數值的變動對最適解的影響。
Nowdays, the enterprise can gain competitive advantages, such as increase profit or reduce cost, through the supplier-retailer cooperation. Due to the imperfect production processes, poor performance of machines, careless of workers, an arrival lot might contains defective items. If retailer sells defective items without inspection, it would cause complaint, returned purchase or lost customers forever. Therefore, selling defective items is a serious problem in business. Besides, trade credit is a common strategy in real market. Supplier offers permissible delay in payments to attract retailer to order more quantity. During the trade credit period, retailer does not have to pay when receiving the products, and can use the sales revenue to earn interest. When the trade credit period is due, retailer has to pay interest for the products still in stocks. And, the delayed payments would produce capital opportunity cost for the supplier.
Two inventory models are developed in this paper. In chapter 2, we established an integrated inventory model with defective items under a two-level trade credit policy. Also, the market demand rate depends on the customer’s credit period. In chapter 3, we established an integrated inventory model with defective items, and assumed that supplier offers an order-size dependent permissible delay in payments. Our objective is to maximize the total profit per unit time. We developed algorithm to obtain the optimal solution for each inventory model. Finally, numerical examples are provided to illustrate the solution procedure and sensitivity analysis is also carried out. |
