Disassembly System Design with Environmental and Economic Parts Selection using the Recyclability Evaluation Method

抄録

To promote a closed-loop supply chain for assembled products, disassembly systems are required to recycle End-of-Life (EOL) products. To increase the total recycling rate of products in disassembly systems, it is desirable to keep rather than destroy parts since disassembly costs are increasing. Therefore, a disassembly system design should be considered based on selecting parts for disassembly in order to minimize the recycling cost while maintaining the recycling rate. On the other hand, since the precedence relationships among disassembly tasks also change according to the parts selection, it is required to consider allocation of the tasks in designing a disassembly line. For the disassembly system design, it is also necessary to have disassembled product information such as the recycling rate and profit of each part, disassembly task times and precedence relationships among the disassembly tasks. This study proposes a disassembly system design with environment and economic parts selection, which balances the recycling rate and cost using the Recyclability Evaluation Method (REM) developed by Hitachi, Ltd. The first step is to optimize the environmental and economic parts selection with integer programming, and the second step is line balancing to reduce the number of stations. Next, a design example is shown and discussed by preparing a 3D-CAD model for a computer and a cleaner. Finally, product and line evaluations are carried out by comparing four scenarios; namely 1) all parts disassembled, 2) maximum recycling rate, 3) minimum recycling cost and 4) balance of recycling rate and cost. It is demonstrated that the recycling cost is reduced as a result of maintaining a higher recycling rate and that the number of work stations and the smoothness index are also improved through use of environmental and economic parts selection.