طراحی شبکه لجستیک معکوس برای یخچال های چند دوره ای Multi-period reverse logistics network design for used refrigerators

1. Introduction Reverse logistics deals with the collection and treatment of used products. Nowadays, apart from economic reasons, organizations across the globe are increasingly focusing on setting up reverse logistics networks owing to the adverse environmental effects caused due to the improper disposal of many used products. However, reverse logistics is still in a state of infancy, particularly in emerging economies (Bouzon et al., [1]). The economic potential associated with used products also makes research in this area quite attractive. According to the Environmental Protection Agency (Dat et al., [2]), there are 20–50 million metric tons of electronic waste (e-waste) alone generated worldwide every year. Thus, organizations must consider the management of reverse logistics systems in addition to forward logistics (Tahirov et al., [3]; Govindan et al., [4]). Moreover, customers are becoming more knowledgeable about environmental pollution and this affects their purchasing decisions (Kara et al., [5]). So, having a proper mechanism in place for a reverse supply chain not only helps firms reduce the negative environmental impact of its used products but also enhances its green image in the markets it operates in (Pishvaee et al., [6, 7]). Original equipment manufacturers and third party logistics service providers often carry out the reverse logistics activities. Many companies such as Kodak, Xerox, HP, Dell and GM focus on remanufacturing and recovery activities, thereby achieving significant gains (Uster et al., [8]). Nevertheless, there are cases where organizations fail to achieve gains from recovery activities. For example, Ford, the automobile manufacturing firm, admitted that automotive recycling was a poor business decision (Karakayali et al., [9]). One of the strategic decisions to be made in a reverse supply chain is the design of the network. This involves the determination of the number and location of facilities to be established. Typically, these facilities include collection centers, disassembly centers, remanufacturing centers, recycling centers etc. The design problem involves the determination of flow between different stages of the network. Reverse logistics activities involve additional supply chain costs which need to be managed. Different recovery options are associated with returned products. They can be remanufactured or the component parts can be repaired or recycled after disassembly. Remanufacturing brings the quality standards of used products up to that of new products (Thierry et al., [10]). Disposal of non-recyclable or hazardous materials is also a difficult task for organizations to carry out; but this too needs to be accomplished. In order to analyze product flows at the component and material levels, it is important to consider the product structure of the returned product by way of taking into account its bill of materials (BOM). Only a few studies have incorporated BOM of the product in the network design of a reverse supply chain (Dat et al., [2]; Alumur et al., [11]; Demirel et al., [12]; John et al., [70, 71]).