Engineering for the Customer: Combining Preference and Physical System Models. Part I—Theory

SUMMARY Engineering products for the customer is difficult. The criteria may be subjective, and often quality and cost are competing objectives which must be balanced. This paper proposes a model which structures the design process, and a methodology to engineer for customer preference. The model links design variables—tangible features of the design concept which can be manipulated by the designer—to multi-attribute value, a number indicating customer preference. Intermediate transfer functions within the model link design variables to system responses, and link specific system responses to value. Thus, customer expectations can be met more effectively, as design variables are related to customer preference in a quantitative way. An iterative design improvement method is considered in which a current design and a new design are compared. The comparison is made by mapping the designs into customer value space, and applying a measure of overall customer preference which considers both cost and a quality attribute.