Supplier selection and evaluation is considered as one of the most critical issues for the success of an organization, as its correctness is directly or indirectly related to the cost, quality and the customer satisfaction. This paper presents a methodology for the supplier selection process in respect to changing customer requirements. It is based on a genetic algorithm that is a search heuristic based on biological evolution. We aim at selecting the optimum supplier set that maximizes the quality, performance of delivery time and minimizes costs at the same time. The proposed management methodology is applied on a real world case in the textile chemicals industry. The results of the algorithm show that the proposed methodology could be used as a decision support system for producers with complex product configurations.