31. Environmental and Economical Design Problem of Upgrading and Remanufacturing Option Selection

In industrial sites where assembled products are produced, usage of natural materials in production is indispensable. Recently, increased consumption and depletion of resources have caused environmental pollution and wastes though components and materials inside products can be reused and recycled by remanufacturing. For a circular economy, upgrading is expected to extend product life and value by replacing some components with higher performance on products. To promote the circular economy, upgrading and remanufacturing selection by disassembly is environmentally and economically required in the manufacturing field. It entails upgrading, remanufacturing, recycling, reuse, and disposal as life cycle options for each component. The upgrading and remanufacturing selection through reutilizing components causes less environmental impacts than producing new components. In addition, upgrading improves the products’ performance and adds value to the product. However, the process of disassembling and reassembling products for upgrading and remanufacturing brings higher labor costs. Therefore, these processes should be harmonized for higher recovery rate and profit simultaneously. In addition, each component’s material has different profits according to the process, and the precedence relationship between disassembled components should be considered. This study addresses an environmental and economical design problem for upgrading and remanufacturing option selection to evaluate the recovery rate and profits. First, the recovery rate and profit for each component’s material are estimated. Secondly, upgrading and remanufacturing option selection is formulated using 0–1 integer programming and ε constraints. Finally, the differences in recovery rates and profits are analyzed.