Influence assessment by index decomposition analysis, prioritizing design variable for ecodesign

In addressing climate change, ecodesign is a pivotal strategy advocating for sustainable products with minimal carbon footprints. However, traditional ecodesign approaches in product redesign often focus on modifying hotspots that may not always reflect the improvement potential or align with the designers' controllable design variables. To optimize ecodesign efforts, this study emphasizes the importance of targeting design variables that exert the most significant environmental sustainability influence on the product. To facilitate such targeted design efforts, an influence assessment was developed to evaluate the environmental sustainability impact of design variables using a four-step framework that adapts Index Decomposition Analysis (IDA). The framework was demonstrated through two redesign scenarios of a handheld fan considering the design tri-factor (choice of material, manufacturing process, and design geometry). In scenario 1, where only the handheld fan's stand was considered, design geometry was identified as the most influential factor in the component's environmental sustainability. In scenario 2, involving four components required to be fabricated from the same material, the material choice was collectively found to exert the greatest influence, even though the stand and battery cover showed alternative design variables with higher influence individually. In both scenarios, the designs generated based on the most influential design variable yielded the lowest carbon emissions among the modifications generated. These results underscore the framework's potential to guide designers towards more effective and sustainable product redesigns.