Increasingly, manufacturers are implementing reverse logistics as part of their overall distribution and supply chain strategy. Reverse logistics has been defined as a process whereby companies can become more environmentally efficient through recycling, reusing and reducing the amount of materials used, according to Craig Carter and Lisa Ellram in The Journal of Business Logistics. Reverse logistics has additional benefits. Some manufacturers want to protect their proprietary and intellectual property knowledge from falling into a competitor's hands. Others want to retain customers by providing spare parts for outdated product models. Still others see an intrinsic value in protecting environmental resources. Before designing a detailed reverse logistics network, two high-level decisions are made at each stage. The high-level decision associated with Stage A is whether to collect the products from individual customers or through a central collection location. In Stage B, sorting and testing could be conducted centrally or in a distributed manner. Finally, in Stage C the return product is reprocessed either at the original manufacturing facility or at a secondary processing facility.