本研究在不完美生產系統中,探討(n+1)次配送與多次配送至多顧客對不良品部分可重工修復之生產系統的生產批量與配送次數之最佳決策。假設生產過程不完美,不良品進行重工前會先篩選無法重工的部分先予以報廢,剩餘之不良品均可以完全修復。 由於傳統經濟生產批量(EPQ)所假設的需求為連續配送與現實情況較為不符合,故本研究為符合實際狀況,探討分期n次配送模式。本研究針對這些假設建立數學模式,期望求得最佳生產批量與最佳配送次數,使期望年存貨總成本最小化。 本研究針對以上之假設建立兩個數學模式:(1) 產品正常生產時間內,當生產足夠供給正常生產時間 與重工時間時所需的量,先行一次配送,重工結束後,再採取分期n次配送且含顧客端存貨持有成本之最佳生產批量及配送次數之決策;(2) 在重工完成後進行分期n次配送至多顧客且包含顧客端存貨持有成本之最佳生產批量及配送次數之決策。最後提出實例來做驗證,並對其參數進行敏感度分析,期望本研究之模式能夠因應實際情況,提供業界處理不良品重工與分期配送上可以作為參考之依據。
This paper determines the optimal lot size and shipments for EPQ models with (n+1) deliveries policy and single-vendor multi-buyer in a supply chain environment with partial reworkable defective items, respectirely. The production process system is imperfect, random defective items are produced due to various inevitable reasons. Not all of defective items are reworkable, a portion of defective items are scrap and are to be discarded before the rework process. Traditional EPQ model assumes a continuous delivery policy, but it is not practical. Therefore, this paper studies a multiple delivery policy to conform to the real-life situation. The purpose of this study is to determine the optimal lot size and delivery policy for such a realistic system in order to minimize its overall costs. Two different models are investigated in this study, they are: (1) (n+1) deliveries policy . (2) single-vendor multi-buyer in a supply chain environment with partial reworkable defective items. In the last, numerical examples are provided to demonstrate its practical usage.