| This thesis identifies and organizes preventive engineering and business approaches that claim to converge business interests with environmental sustainability. It then assesses the two preventive approaches with the greatest expected environmental benefits---selling services instead of products and product take-back---in terms of their throughput advantages and environmental advantages.; The approach of product take-back can be broken down into two engineering and business choices that companies can consider: (1a) fabricating materials from virgin resources or (1b) fabricating them from recovered materials and (2a) fabricating components from virgin materials or (2b) remanufacturing them from components retrieved from disassembled, worn out products. Options a (the conventional approaches) and b (the alternative approaches) within the two sets of choices are compared.; A comparative analysis of options 1a and 1b is undertaken for three materials: aluminum, steel and plastic. It consists of presenting life cycle inventories that indicate the throughput of matter and energy involved in each of the options based on data in the literature. Because of throughput advantages (lower waste treatment and disposal costs, fewer non-saleable products flowing through the facility leading to reduced capital, maintenance and energy costs and lower risks), the option with lower throughputs is likely to reduce costs. The life cycle inventories are used to calculate environmental impact indicators. These indicators are a measure of contribution to specific environmental problems. In general, it is found that option 1b has throughput advantages and environmental advantages over option 1a.; The comparison between option 2a and 2b is undertaken using case studies of German end-of-life vehicles, Xerox photocopiers and IBM computers. Here the data are limited and scattered, but suggest that the throughput advantages and environmental advantages are considerable.; The additional benefits to be expected from selling services instead of products, above and beyond what can be expected from the product take-back approach, could not be assessed due to the unavailability of data.; The thesis identifies barriers to the implementation of the preventive approaches and concludes that research into how to overcome these is worthwhile given the considerable throughput advantages and environmental advantages. |
