The manufacturing industry is facing the challenge of how to create a product with less impact on the environment for a more sustainable society, and green design plays a critical role in this. Green product design is defined as the practical application of factors that can reduce the environmental impact of products during the design phase. Some design methods have been proposed for green product design, such as design for modular (DFM), design for disassembly (DFD), and design for regeneration (DFR). DFM is further extended to “design for green modular”. Because this can improve the environmental effectiveness of products, green modular design is now regarded as an important design method.