AbstractSales and marketing people routinely evaluate and rank their customers to develop a marketing strategy and plan of action for utilizing available sales resources. Performing this evaluation informally makes it difficult to take into account all the significant customer attributes in a consistent and objective manner. In this paper an approach based on multiple attributes is developed to assist in evaluating customer performance. This approach is coded primarily in an expert system shell, which is run on a personal computer. The expert system shell was chosen over other software by the marketing people because they preferred its user-friendly capabilities. This system is being used by the Tin Mill Products Marketing office of Bethlehem Steel and is being considered for use by other product-line marketing offices within Bethlehem.