An integrated approach for design concept evaluation based on interval-valued Pythagorean fuzzy set and consensus model

Purpose Design concept evaluation overwhelmingly impacts product development. This study aims to enhance uncertainty representation in the design concept evaluation process, consider the impact of evaluators’ cognitive bias on the evaluation results and improve the credibility of the evaluation results. Design/methodology/approach This study proposes an integrated approach for design concept evaluation based on interval-valued Pythagorean fuzzy set (IVPFS) and consensus model. In this study, we introduced IVPFS to represent the evaluation and preferences of the evaluators, then built a consensus model based on mathematical operators to measure the degree of cognitive consistency among evaluators, applied the modification of non-consensus opinions through a feedback mechanism to reach consensus, and finally, ranked all design concepts by the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Findings The results indicate that the proposed approach is an objective and effective solution for representing individual differences and reducing the impact of group heterogeneity. Research limitations/implications The number of evaluators in the numerical example is insufficient for realistic design activities. We aim to address this issue in future studies. Practical implications The proposed method contributes to the smooth implementation of design concept evaluation and the construction of harmonious interpersonal relationships within organizations. Social implications The proposed method contributes to the smooth implementation of the design concept evaluation as well as the construction of harmonious interpersonal relationships within the organization. Originality/value This method addresses the subjectivity of the evaluator and the uncertainty of information in the evaluation process, reduces the impact of evaluators’ cognitive differences on the evaluation results, and ultimately selects a robust design alternative under these circumstances.