Nexus Between Life Cycle Assessment, Circularity and Sustainability Indicators—Part II: Experimentations

Considering the growing number of metrics and indicators to assess the circular economy transition, it is paramount to shed light on how they complement and differ from traditional approaches, such as life cycle assessment or sustainability performance indicators. This study provides new empirical insights on the correlation between life cycle assessment, circularity, and sustainability indicator-based approaches to design circular and sustainable products. Specifically, the importance lies in analyzing how the results generated by these different approaches can be used to support the design of products that are not only circular but also sustainable. A practice-based project, involving over 175 engineering students over two consecutive academic years, is conducted with the purpose of comparing and improving the circularity and sustainability performance of three product alternatives of lawn mowing systems (gasoline, electric, autonomous). Notably, the following resources are deployed: 18 midpoints environmental indicators calculated by life cycle assessment, nine product circularity indicators, and numerous leading sustainability indicators. Critical analyses on the usability, time efficiency, scientific soundness, and robustness of each approach are drawn, combining quantitative results generated by each group with the feedback of future engineers. Last but not least, the developed workshop could be reused or adapted to train further the designers, engineers, and managers of tomorrow in deploying life cycle, circularity, and/or sustainability-indicator-based approaches to make more informed and sustainable decisions, e.g., between design trade-offs.