Multiattribute utility theory is commonly used to define and represent the decision-maker's preferences under conditions of uncertainty and risk. A major issue in implementing this approach deals with the identification and generation of appropriate utility functions, especially in an often nonlinear and complex engineering design environment. Typically, the decision-maker's preferences are provided through lottery questions rather than based on deductive reasoning to reflect the nonlinear tradeoffs among the attributes. The use of such an intuitive procedure can lead to inconsistent and inexact preference information that may result in inaccuracy and rank reversal problems. Alternatively, this paper presents an Interactive Preference-Modeling (IPM) method towards a consistent preference representation in engineering design. Focusing on the preference orientation by implicitly articulating the designer's priorities, this method provides a methodical framework to check and eliminate inconsistency in preference information, and to accurately express preferences through rational pairwise comparisons. The development of IPM method and its utilization in the determination of the system utility function from a consistent set of local utility functions are presented in the context of a beam design problem and the results are discussed.