energies Article Metrics for Measuring Sustainable Product Design Concepts Ji Han 1,*, Pingfei Jiang 2 and Peter R. N. Childs 3 1 School of Engineering, University of Liverpool, Liverpool L69 3BX, UK 2 Department of Mechanical Engineering, Kingston University, London SW15 3DW, UK;
[email protected] 3 Dyson School of Design Engineering, Imperial College London, London SW7 2DB, UK;
[email protected] * Correspondence:
[email protected] Abstract: Although products can contribute to ecosystems positively, they can cause negative envi- ronmental impacts throughout their life cycles, from obtaining raw material, production, and use, to end of life. It is reported that most negative environmental impacts are decided at early design phases, which suggests that the determination of product sustainability should be considered as early as possible, such as during the conceptual design stage, when it is still possible to modify the design concept. However, most of the existing concept evaluation methods or tools are focused on assessing the feasibility or creativity of the concepts generated, lacking the measurements of sustainability of concepts. The paper explores key factors related to sustainable design with regard to environmental impacts, and describes a set of objective measures of sustainable product design concept evaluation, namely, material, production, use, and end of life. The rationales of the four metrics are discussed, with corresponding measurements. A case study is conducted to demonstrate the use and effectiveness of the metrics for evaluating product design concepts. The paper is the first study to explore the measurement of product design sustainability focusing on the conceptual design stage.