Case Study: A Product Line Analysis for Eco-Designed Fashion Products

Eco-design is vital for sustainable fashion product line development, as many decisions in terms of sustainability are decided at the design stage. According to the theory of the Triple Bottom Line, the impact of eco-design could be divided into three aspects: economic, social, and environmental. Design includes developing manufacturing processes, selecting materials, managing transportation modes, and extending product life cycles. Clark et al. proposed four key approaches to eco-design in the real world of fashion: (1) new product design, (2) redesign, (3) incremental design, and (4) radical design. Lee demonstrated that sustainable design and sustainable production means designing and producing products with less resource consumption and less impact on the environment. Köhler argued that eco-design mainly addresses a variety of aspects in a product's environmental impacts such as material selection (e.g., non-toxic substances, organic materials, recyclable materials), choices of production processes (e.g., low-carbon emission and waste production), and end-of-life treatment (e.g., repair and recycle). Cimatti et al. examined eco-design and sustainable manufacturing in luxury fashion. They argued that life-cycle assessments (LCAs) could enhance sustainability in fashion by describing the case of a prestigious Italian luxury fashion brand. De Angelis et al. evaluated the impact of design on luxury fashion green products. They conducted three experiments and identified that the new green luxury product design is more similar to the luxury company's previous models instead of the similar models produced by green companies.

For eco-material selection, sustainable fabric choices are limited compared to the conventional options. It causes much difficulty for sustainable fashion designers when integrating function, aesthetic, and sustainability into product design. Allwood et al. compared the energy consumption for a cotton t-shirt and a viscose blouse. They found that producing a viscose blouse can save energy compared to producing a cotton t-shirt. This result implies that if the aim of a fashion designer is to develop a green product with low-energy consumption in the production stage, using viscose as the raw material is more desirable when compared with cotton.

Eco-design considers product life cycle and end-of-life treatment in product line development. Armstrong and LeHew argued that eco-design is different from traditional design because designers must reconcile conflicts between functional priorities. They summarized several sustainable product development approaches adopted in sustainable apparel product development, such as life-cycle assessment (LCA). In the textile and apparel industry, LCA is important to consider in the area of textile-related product design. The well-known example of conducting LCA in product development is Patagonia. Zamani et al. evaluated a carbon footprint of textile recycling. They tested different textile recycling techniques with product life cycle assessment. As a result, designers selected the proper raw material in the product design stage and the suitable production process in the process design stage. For example, the designers selected the degradable materials in raw-material selection if the used products collected from secondhand shops and charity systems were treated by landfill disposal. Niinimäki and Hassi argued that the sustainable fashion designers should consider the frequency of apparel wash in terms of product lifespan in the eco-design stage. If the product has a long lifespan, designers should pay attention to aesthetic longevity and consider classic styles and colors. Moon et al. developed guidelines for the design and production of sustainable energy-saving fashion products. They argued that fashion products can use eco-materials through the manufacturing, utilization, and disposal stages. Consistent with Moon et al., we considered various eco-materials in fashion product line development. The use of eco-materials is one of the indicators for sustainable fashion, i.e., the more eco-materials that are used, the higher the degree of sustainability for each product.