Preference Consistency in Multiattribute Decision Making

A number of approaches for multiattribute selection decisions exist, each with certain advantages and disadvantages. One method that has recently been developed, called the Hypothetical Equivalents and Inequivalents Method (HEIM) supports a decision maker (DM) by implicitly determining the importances a DM places on attributes using a series of simple preference statements. In this and other multiattribute selection methods, establishing consistent preferences is critical in order for a DM to be confident in their decision and its validity. In this paper a general consistency check denoted as the Preference Consistency Check (PCC) is presented that ensures a consistent preference structure for a given DM. The PCC is demonstrated as part of the HEIM method, but is generalizable to any cardinal or ordinal preference structures. These structures are important in making selection decisions in engineering design including selecting design concepts, materials, manufacturing processes, and configurations, among others. The effectiveness of the method is demonstrated and the need for consistent preferences is illustrated using a product selection case study where the decision maker expresses inconsistent preferences.