The basic idea of Quality Function Deployment(QFD) is to deploy the voice of customers into the final product through product planning, part planning, process planning, and manufacturing. In the product planning stage, which is the first stage of product development, customer attributes(CAs) are translated into engineering characteristics(ECs). Then, based on the relationship between CAs and ECs, the target values of ECs are determined. In the previous research, the process of analyzing these relationships is mostly subjective in nature. In this article, we formulate the process of determining the target values of ECs as an optimization model. That is, we first determine the relationship between CAs and ECs as cumulative logit models and construct constraints into which the company strategy as well as the needs of customers can be incorprated. Next, cost functions of ECs are developed, which are summed into an objective function. An algorithm to solve the formulated optimization problem is developed and illustrated with an example.