Quantifiable measures of sustainability: a case study of materials selection for eco-lightweight auto-bodies

The authors propose an eco-material selection approach based on a set of quantifiable measures for developing a sustainability model within the context of an automobile structure or Body-In-White (BIW). As the established sustainability model consists of both quantitative and qualitative factors, the qualitative factors were transformed into numerical values prior to performing the materials selection process, aided by the Preference Selection Index (PSI) and Principal Component Analysis (PCA) decision-making/supporting tools. The uniqueness of this study comes from using PCA as a scoring tool which is benchmarked against another scoring tool (PSI); however, both PSI and PCA avoid the bias that typically arises from assigning weights to different design attributes, as it is not necessary to assign a relative importance scheme between candidate materials. In this study, however, the authors detail the potential of this objective selection scheme to balance the technological, economical, societal and ecological constraints in the design of automobile bodies.