## 1 Introduction  
With the rapid development of civil aviation industries in the world, increasingly higher requirements have been proposed for the spare parts support capacity of civil aircrafts in recent years. According to statistics from TeamSAI, the spare parts stored in the global civil aviation industry are about USD 50 billion at present, accounting for 75% of the stock capital and 25% of the working capital of airlines. However, the utilization rate and turnover rate of most spare parts for civil aircrafts are extremely low, and only 25% of the spare parts have been utilized [1]. Therefore, the scientific and reasonable spare parts support capacity evaluation based on the actual needs of the civil aviation industry for spare parts support capacity is not only an important guarantee for the spare parts support efficiency of civil aircrafts but also a realistic need for promoting the further development of the civil aviation industry. At present, the research work on aircraft spare parts support mainly focuses on two aspects: on one hand, the demands for aircraft spare parts have been predicted [2; 3], i.e., estimating and predicting the specific number of the spare parts needed within a certain period of time in the future according to the actual operation status, maintenance period,and other factors of civil aircrafts; on the other hand, the inventory of aircraft spare parts has been optimized [4], namely, in ensuring the abundant supply of aircraft spare parts to the greatest extent by reasonably analyzing and adjusting the inventory level, taking acquisition strategies and implementing supply chain management, and effectively controlling the inventory cost and reducing the inventory risk on the premise of guaranteeing flight safety. For instance, [PERSON] et al. [5] used the Holt-Winters exponential smoothing method to forecast the demand for spare parts in view of the seasonal factors affecting spare parts consumption. [PERSON] et al. [6] put forward a new spare parts inventory control strategy to shorten the maintenance time of civil aircraft components and solve the failure of the existing spare parts inventory methods to meet the needs of aircraft operators. More detailed research content can be found in references [7; 8; 9]. It can be seen that abundant research results have been achieved regarding the above-mentioned two aspects, but the evaluation of the spare parts support capacity of civil aircrafts has been involved in a very limited way. In fact, only by scientifically assessing the spare parts support capacity of civil aircrafts can the weak links of spare parts support be accurately identified, and the spare parts support capacity can be improved in a targeted manner. Assessing the spare parts support capacity of civil aircrafts is to determine the evaluation values of different civil aircraft spare parts support solutions under the corresponding evaluation indicators based on the information provided by many experts, and then rank such solutions to determine the spare parts support effect. Hence, the evaluation of the spare parts support capacity of civil aircrafts is, in essence, also a multi-attribute decision problem. It is effected by the different knowledge levels of different decision-making groups, however, their decision opinions are usually very uncertain [10]. Since the decision process involves the evaluation of multiple solutions [11; 12], decision experts possessing rich professional knowledge and work experience in relevant fields should be selected according to the specific evaluation backgrounds so that the decision opinions given by decision groups are relatively fair and reasonable. In addition, to assess the spare parts support capacity of civil aircrafts based on the idea of a multi-attribute decision, the decision information should be expressed in appropriate manners to provide a basis for the subsequent multi-attribute decision operation.