为了保证航空装备的可靠性、安全性，提升系统的测试、维修与保障能力，对系统测试性提出了更高的需求。通过系统测试性问题分析，综合考虑系统功能重要度、失效率、故障风险影响、可测试性等要素，建立系统测试性目标函数模型；研究基于功能重要度分析、功能失效风险与失效率分析、故障树分析和可测试性技术在复杂系统测试性目标确定中的方法应用。通过航空辅助动力装置控制系统测试性目标选取表明，所提出的方法可以实现动力控制系统中的功能重要度与风险项分析，并且能够指导开展高风险项的测试性设计。

In order to ensure the reliability and safety of aviation equipment and improve the testing, maintenance and support capabilities of the system, higher requirements were proposed for system testability. The testability objective function model of the system was established by analyzing the testability problem of the system, considering the system function importance, failure rate, failure risk effect, testability and other factors. The application of functional importance analysis, functional failure risk and failure rate analysis, fault tree analysis and testability technology in the determination of testability targets for complex systems was studied. Through the analysis and calculation of testability target selection in auxiliary power unit (APU) control system, it is show that the proposed method can realize the analysis of functional importance and risk items in the power control system, and can guide the testability design of high risk items.