Design concept evaluation in product development using rough sets and grey relation analysis

Design concept evaluation plays a critical role in the early phases of product development as it has significant impact on the downstream development processes as well as on the success of the product developed. Essentially, design concept evaluation is a complex multi-criteria decision-making process involving large amount of data and expert knowledge which are usually imprecise and subjective. Aiming to improve the effectiveness and objectivity of the design concept evaluation process, this paper proposes a novel method based on grey relation analysis and rough set theory. By integrating the strength of rough sets in handling vagueness and the merit of grey relation analysis in modeling multi-criteria decision-making, a rough number enabled grey relation analysis (called rough–grey analysis) is proposed to evaluate design concepts. The result of an example shows that the proposed rough–grey analysis has provided a novel alternative to perform design concept evaluation, in which the vague design information and expert knowledge can be modeled and analyzed more effectively and objectively.