Weighted matrices as product life cycle assessment tools

Experience demonstrates that comprehensive life cycle assessments (LCAs) for complex manufactured products are too data-intensive and too costly, and the results too uncertain, to be useful as regular tools for the product designer. In their place, streamlined LCAs, preserving the concepts of evaluating all product life stages and a range of environmental concerns yet doing so in semiquantitative and much more efficient ways, are becoming common. They suffer, however, from an inability to prioritize and emphasize the most important life stages and environmental concerns. This paper presents a methodology for using weighted matrices to accomplish this latter goal while preserving much of the straightforward approach and efficient information display attributes typical of unweighted, streamlined LCAs. The techniques are demonstrated by performing assessments on generic automobiles of the 1950s.