在自由開放的競爭市場下,有效的降低企業成本及增加產品的價格是提高競爭力的不二法門。近年來隨著地球資源逐漸枯竭及環保意識的抬頭,物料成本占企業總成本的比重日益增加。資源回收與再利用是為了能夠達到物盡其用,不浪費資源,不僅可以降低新物料的購買成本,亦可減少對自然環境的破壞。本研究主要是針對回收舊紙與再製造程序的部份,分別從回收商及造紙商的角度,探討雙方逆物流的存貨模式。回收商的回收價格直接影響回收率及其利潤,而造紙商除向原物料供應商訂購原物料之外,另需向回收商收購回收舊紙,處理轉換成回收物料後,再依特定比例混合原物料進行生產。在考量回收價格、回收率、原物料價格、需求率及生產率等條件下,本文建構了雙方各自的利潤函數,並分別求出回商最佳的回收價格,以及製造商經濟生產批量與向供應商、回收商訂購原料、回收料的最佳訂購量。最後以數值範例說明所建構之逆物流存貨模式的實用性。
The material cost of the company in recent years has increased noticeably with gradual depletion of the Earth's resources and the rise of environmental protection consciousness. Reusing the recycled materials not only can reduce the purchase cost of virgin materials but the damage to the natural environment. This study is mainly for the part of the wastepaper recycling and remanufacturing process to study both of the reverse logistics inventory models from recycler and manufacturer perspectives. The price of reclaiming will affects the return rate of wastepaper and the profit of recycler. On the other hand, manufacturer besides orders virgin materials from pulp supplier, also purchase wastepaper from recycler. The enterprises may add in recycled materials in accordance with the specific proportion mixed virgin materials while manufacturing their products. In considering the price of reclaiming and virgin material, the return rate of wastepaper, the rate of demand and productivity and other conditions, the profit models have been constructed of recycler and manufacturer, respectively. Therefore, we obtain the optimal reclaiming price, economic production and order quantity by maximizing their profits.