Design for environment development at Motorola

Abstract

Increasing market opportunities in the European Community require product lifecycle impact analysis early in the design stage. Decisions such as material selection and processing ultimately have a big impact on our environment. In this paper, we present a system for evaluating the environmental impact of product designs. This system has as its core a staged approach which matches analysis tools to appropriate stages in product design. In the first stage, when little detailed information is available about a product, matrix approaches are used. These have been pioneered by Graedel and Allenby (1994, 1995). We have adapted the matrix method to match the sphere of influence of our design team and the likelihood that change can be made. The focus is to make changes where possible while still including impacts from outside our sphere of influence. The second stage in product design starts during the design of piece parts. After considerable search for a design tool for this stage in product development, at the time no tools were available. To meet the needs of designers during this stage we developed a software system for determining an environmental score, beginning with RF shield components and continuing with other design applications. A team of engineers and researchers from across the corporation determined eight criteria to measure the shield's environmental score. The criteria are diverse (different ranges, units, and importance levels); they are often in competition with each other (improvements in one result in worsening of others); and each impacts the overall score differently. These factors are all considered in the scoring system. A decision analysis method was used to combine the eight criteria into a single metric. A Value function for each criteria was constructed based on its impact. The combination of impacts, or values, were aggregated into an overall multicriteria value function. The overall environmental score depends the current values of all criteria as well as the importance weightings for each. The weightings represent allowable tradeoffs between competing criteria. The environmental scoring software can easily be extended to evaluate the environmental impact of other mechanical design applications including housings and packaging. Work is underway to extend the system application to whole products. In the final stage of product design, prototype manufacture, traditional life cycle tools can be employed. The scoring algorithms developed in the previous tool can be used for assessment of the results of a Life Cycle Inventory. Although Life Cycle Assessment (LCA) has not been performed on a Motorola product, it is expected that as LCA matures LCA studies will become more common.