在現今供應鏈的環境中要成功運用及時化生產需要買方與賣方一種新的合作精神。企業實施及時化採購以獲得與維持企業的競爭優勢。及時化採購優點為買方與賣方密切合作，長期採購合約約定賣方少量多次的小批量運送高品質產品，以降低存貨水準及減少設置與訂購成本。
一個整合存貨模式是基於考慮一般存貨決策與企業功能下總成本最佳化。然而在大部份相關文獻中均假設年需求與生產率已知，並不實際。本論文中假設模糊年需求與模糊生產率，運用精簡距離法排序模糊數，去尋找估計模糊語意下的一般總成本，而後得到相應最佳買方的購買數量和每一個品項從賣方運送到買方的整數批次。最後以範例提供說明假設模型的結果。

The successful implementation of JIT production in today’s supply chain environment requires a new spirit of cooperation between the buyer and the vendor. Companies are using JIT purchasing to gain and maintain a competitive advantage. The benefits of JIT purchasing include small lot sizes, frequent deliveries, consistent high quality, decrease in inventory levels, lower setup cost and ordering cost, and close supplier ties.
An integrated inventory model with such a consideration is based on the total cost optimization under a common stock policy and business formula. However, the supposition of known annual demand in most related literature may not be realistic. This paper proposes the inclusion of fuzzy annual demand and/or the production rate, and then employs the signed distance, a ranking method for fuzzy numbers, to find the estimate of the common total cost in the fuzzy sense, and subsequently derives the corresponding optimal buyer’s quantity and the integer number of lots in which the items are delivered from the vendor to the purchaser. Numerical examples are provided to illustrate the results of proposed models.

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