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To combat the environmental issues posed by global warming and the depletion of natural resources, the emission of greenhouse gases (GHG) and the consumption of natural resources must be economically reduced. Upgrading and remanufacturing are expected to play important roles in dealing with both issues since they can save the production of virgin materials associated with GHG emissions for assembled products by component reuse and material recycling. Although upgrading components can add additional values and avoid their value obsolescence, composing reused components with shorter physical or value lifetime in a remanufactured product leads to decreasing revenue from selling the upgrade-remanufactured product. Hence, in these cases, component reuse and material recycling can be more economical life cycle option than upgrading and remanufacturing. Furthermore, disassembly is an essential process for recovery options such as upgrading, remanufacturing, components reuse, and material recycling, and tends costly due to the labor costs of manual disassembly. Disposing without disassembly may be a better life cycle option. Therefore, life cycle options, including upgrading, remanufacturing, reusing, recycling and disposal should be suitably selected for each component based on an additional value by upgrading, physical and value lifetimes for each component. This study proposes an upgrade-remanufacturing decision method to maximize GHG saving rate and profit using 0-1 integer programming with ε constraint method. The numerical experiments are conducted using the laptop consisted of 34 components. The results in the laptop indicate that the selling price of upgrade-remanufactured product should be set to more than 2,000 Yen, and the achievement of much higher GHG saving rate such as 99% would lead to negative earnings. Additionally, the bi-objective model is expanded to multi-objective for profit, GHG saving, and recovery rates for investigation of the profit and the selected life cycle options for each component.

The concept of universal design (UD) has received significant attention from researchers, but it remains difficult for UD designers to reflect the diversity of the users in the product. Previously, we proposed a set-based UD method that considered the diversity of a user’s physical characteristics; however, this method did not take into account the requirements of a diverse set of users. Therefore, the present study proposes a new UD concept that quantitatively incorporates the diverse requirements of various users. Exploiting the concept of an evaluation grid and a set-based design method, this paper explains the procedure of our UD method from the determination of user requirements and design variables to the derivation of design solutions satisfying all users. We choose the problem of designing a mechanical pencil as a case study for our proposed method. Pair-comparison tests of mechanical pencils are conducted, and an evaluation structure diagram for a mechanical pencil is constructed on the basis of the results of this experiment. The importance of the design variables is calculated quantitatively based on the evaluation structure diagram, and the key design variables are determined. After the classification of users, we derive the design-ranged solutions for each group of users and the common design-ranged solutions for all users. Our proposed method successfully derives five types of mechanical pencils that together satisfy all users belonging to various user groups.

To utilize the residual value, which remains an idle asset and disposed product based on the circular economy package, the definition or clarification of such a value and the development of a scheme for such a reutilization is essential. In addition, to facilitate an efficient utilization of the residual value, a product or its components needs to be designed considering its future reuse, remanufacturing, and upgrading. When companies monitor product usage using the Internet of things, they can make proposals to users of appropriate lifecycle options such as reuse, remanufacturing, and upgrading and such proposals are conductive to customer retention for these companies. Therefore, an ideal situation is one in which the product is appropriately modularly designed and its components will be reused in an upward product or another product family or be recycled at the end of life. A designer needs to consider resource efficiency not only in the reuse stage but also in the production and procurement stages. In addition, a company that designs and manufactures products needs to strive for the simultaneous attainment of cooperate social responsibility, higher profits, and higher user satisfaction. Therefore, proper supplier selection is necessary because products currently consist of many components and modules manufactured by various companies. This study proposes a modular design and a strategic evaluation method based on the viewpoint of supply chain management considering sustainability and supplier selection simultaneously. In particular, the proposed method evaluates the designed modular strategy from the perspectives of cost, environmental load in production and transportation, quality, and procurement lead time. As an evaluation, the proposed indicator evaluates the efficiencies of the candidate suppliers. This study applied the proposed method to the design problem of a laptop module and determined the more appropriate suppliers with respect to each destination.

The depletion of natural resources and global warming have increased in severity globally. In the industrial field, assembly products, such as electronic products, should be disassembled for recycling and reuse to deal with these problems. Reuse and recycling can contribute to reducing GreenHouse Gas (GHG) emissions and less depletion of natural resources since GHG emissions for virgin material production can be saved using reused components and recycled materials. However, each component of selling revenue and material-based GHG emissions depends on the country because of the different energy mixes of electrical power. Moreover, each collected component embedded in End-of-Life (EOL) products needs to be selected as a life cycle option based on its remaining life. The purpose of this study is to decide life cycle options such as reuse, recycling, and disposal of each component environmentally-friendly and economically in Korea and Japanese cases for computers. Firstly, selecting the life cycle option for each component was formulated by 0–1 integer programming with ε constraints. Next, GHG emissions, profits, and costs in Korea and Japan were estimated and analyzed for each component. Finally, Korean and Japanese cases were analyzed to obtain an economic value in the same material-based GHG saving rate with each component’s life cycle option selection by comparing each EOL product data. In the experiments, GHG recovery efficiency was higher in Japan 43 [g/Yen] than one in Korea 28 [g/Yen]. Therefore, it was better to retrieve and reutilize the components in Korea. However, if the maximum GHG recovery efficiency is desired, Japan is a better option.