Considering customer preferences for environmental protection in material selection Deborah L. Thurston, Shannon M. Lloyd and Joseph Wallace Decision Systems Laboratory, Department of General Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA Received 7 March 1994; accepted 20 July 1994 This paper presents a method for integrating environmental considerations directly into the material selection process. A design hierarchy is used to perform concurrent multi-attribute material evaluation on the basis of cost, physical properties and customer preferences. A proof- of-concept case study of material selection for beverage containers is presented. The results of a consumer survey are reported. Trade-offs between aluminium, glass and plastic containers are analysed. The price reduction necessary to make plastic competitive with aluminium for a par- ticular market niche is calculated. Keywords: environment; customer preferences; materials selection Introduction Engineers are attempting to respond to an increased awareness of the need to protect the environment. During the task of material selection, designers are beginning to consider product life-cycle issues, such as recyclability. In situations where the environment can be protected while simultaneously lowering cost and improving quality, the choice is obvious. When envi- ronmental protection can be achieved only through a price increase, the choice is less clear. In the market- place, it is the customer who identifies the 'best' mater- ial overall when he or she makes purchasing decisions. Unfortunately, there is sometimes a difference between what customers say they are willing to pay for a hypo- thetical new product and what they are actually willing to pay when the product becomes available. This paper describes a method for integrating cus- tomer responses to environmental issues into the mate- rial selection process. The next section first describes the motivation for developing such a method. Then the third section describes the method in general terms and the reasoning behind its structure. The fourth section presents an example application of material selection for beverage containers, and reports on a survey of customers' willingness to sacrifice convenience and cost savings for environmentally safer packaging. Motivation In a global economy almost all industry finds that it needs to design and manufacture better products just to stay competitive. In an attempt to improve the product design process many companies are now in a transi- tional state moving from what we refer to as 'compart- mentalized' design into concurrent design. In the past, compartmentalized design was the natural result of the institutional barriers separating the design, manufactur- ing, marketing and customer-use activities. This has proven to be unsuccessful. Concurrent design incorpo- Correspondence to Deborah L, Thurston rates design, manufacturing, marketing and customer preferences directly into the design process. One approach is quality function deployment (QFD), which helps designers to organize information about the 'voice of the customer' into a matrix format which clarifies the connections between customer desires and engineering parameters'. The goal of concurrent design is a product that is inexpensive and easy to manufacture and assem- ble, which simultaneously satisfies product requirements and customer desires. Participants in this design process must be able to see how their individual parts fit into the total design of the product. This is not simply a desirable objective, it is considered to be essentiaF ~. We believe that the next logical step is to incorporate envi- ronmental issues into the concurrent design process. Just as efforts to design for manufacturing helped to reduce manufacturing costs, so too should designing for the environment help to reduce detrimental impacts on the environment as well as the costs of waste treatment and disposal. Manufacturers in several European countries are incorporating environmental concerns into the design process. Henk Folmer, president of the European Association of Environmental Resource Economists, has said that businesses in France, Germany and else- where have targeted 'Clean Technology' as a way to increase employment and gain a competitive edge in the supply of future goods and services 5. Efforts have been made at designing products that are easily recyclable, and redesigning older products to make them more environmentally compatible6. As the two global trends of trade liberalization and environmental protection continue, the profitable companies of the next century will be those capable of designing products and manu- facturing processes for environmental compatibility. Rising customer concerns over environmental condi- tions and toxic waste are also forcing companies to take a new look at the way their products are designed, man- ufactured and packaged. Today packaging material is the largest component of our solid waste stream, accounting for almost one-third of municipal solid 0261-3069/94/040203-07 © 1994 Butterworth-Heinemann Ltd Materials & Design Volume 15 Number 4 1994 203