A design methodology for the strategic assessment of a product's eco-efficiency

The growing number of manufactured products has given rise to an alarming increase in the volume of industrial waste that is threatening the environment. However, if the various stages of a product are designed to be environmentally sustainable, ecological damage can be minimized, if not eliminated. This paper discusses a methodology that scores the cost, quality and environmental standing of four stages of the life cycle of a product. This is achieved through eight indices, or metrics, which depict the environmental standing of the product. The eight indices cover product cost, product reliability, serviceability and product retirement, among others. A self-learning algorithm is discussed that computes the best and worst values of the indices from a variety of similar products. This enables the designer to build up a comprehensive database of environmental data of a product. When displayed in a radar chart, the indices allow the environmental standing of a product to be quickly assessed, or compared with competitor designs. To emphasize their relative importance, weights may be assigned to the indices. Four case studies are presented and discussed. In the case of the injection-moulded multi-purpose holder, it was found that its reliability could be improved at the expense of manufacturability and retirement options. The eco-indices of 15 specimens of telecommunications paging devices, 13 amp 3-pin electrical plugs and 360 ml moulded drinking cups were computed and plotted on a radar chart. Overall, the analyses revealed that the five models of telecommunications pagers were not designed for end-of-life disposal and that the eco-efficiency of the electrical plugs depended on their country of manufacture, the ones made in the West being more environmentally benign. The drinking cups, on the other hand, illustrate the relative impact of different materials on the environment. The methodology can potentially benefit product designers, manufacturing engineers, sales/marketing personnel, in fact, all who have vested interests in environmentally friendly product design.