Design concept evaluation is one of the most important phases in the early stages of the design process as it not only significantly affects the later stages of the design process but also influences the success of the final design solutions. The main objective of this work is to reduce the imprecise content of customer evaluation process and thus, improve the effectiveness and objectivity of the product design. This paper proposes a novel way of performing design concept evaluations where instead of considering cost and benefit characteristics of design criteria, the work identifies best concept which satisfy constraints imposed by the team of designers on design criteria’s as well as fulfilling maximum customers’ preferences. In this work, the rough number enabled modified Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method for design concept evaluation is developed by modifying the extended VIKOR method with interval numbers. The proposed technique is labeled as modified rough VIKOR (MR-VIKOR) analysis. The work primarily involves two phases of concept evaluation. In the first phase, relative importance ranking and initial weights of design criteria are computed through the importance assigned to each design criteria by the designers or the decision makers (DM); and in the second phase, customers’ preferences to the generated user needs are captured in the form of rough numbers. The relative importance ranking computed in first phase along with customers’ preferences is incorporated in the second phase to select the best concept. 
Product design concept evaluation using rough sets and VIKOR method