Abstract: In response to the lack of evaluation system and methods for the impact of product design change on production plans, the study takes Company L, an aviation parts manufacturing enterprise, as a case study to construct a three-dimensional evaluation index system for time, cost, and quality. A combined weighting method based on ‘extensible analytic hierarchy process - improved CRITIC method - entropy weight method’ is proposed. Firstly, by analyzing the impact of design change on output value, variety, quality, and schedule in the production plans, 8 key indicators are selected. Then, based on expert experience and data characteristics, a linear weighting method is used to balance subjective and objective weights and avoid single weighting bias. The case analysis shows that the overall level of the impact of customer AE008's design change on production plans is not high. The scores of the impact of 9 product design change on production plans range from 0.028 to 0.839, with an average of 0.256. From the data of the 3 product categories with scores higher than the average, it can be found that the main indicators affecting the scores are time and cost indicators, especially the change rate of design change order delivery time and the production cost of design change. The study has solved the problem of one sidedness in the existing weighting methods for evaluation of production plans, and quantified the specific impact of design change on production plans through actual data, providing a theoretical basis and feasible approach for manufacturing enterprises to evaluate design change.