Lastik geri kazanımı için lojistik ağ modeli tasarımı: Vaka çalışması

We consider the problem of designing a logistics network for the collection and reprocessing of used tires. The logistics network consists of used tires collection points, recycling and/or remanufacturing facilities and demand points. Tire remanufacturing, commonly known as tire retreading, and tire recycling are very profitable, yet many companies who reprocess used tires are mostly either doing only recycling or only retreading. Retreading-only companies usually use a make-to-order system where the customers bring them their own tires to be retreaded, i.e. there is one-to-one correspondence between returns and customer orders, whereas recycling companies use a make-to-stock system where the used tires are collected back and after recycling, the resulting products are sold to manufacturers to be used as raw materials or energy sources. We investigate the profitability of adding a tire retreading facility into the logistics network for a company who originally does recycling only. The problem is formulated and solved using mixed integer programming for both single-period and multi-period cases in order to find the optimal design that maximizes the overall profit of the recycling company. Numerical experimentations are conducted to see the effects of changing return parameters on the optimal design and profit.