安全关键可编程系统应用软件功能安全分析要点浅析

Key Factors for Functional Safety Analysis against Application Software of Safety- Critical Programmable Systems

安全关键可编程系统是安全关键应用领域的基础设备。为确保安全关键可编程系统的整体功能达到所需的高安全度,有必要对其应用逻辑软件进行功能安全分析。应用逻辑软件的多样性,为进行准确的功能安全分析增加了难度。本文在分析安全关键可编程系统基本结构及其软件基本特性的基础上,通过简化领域相关性,针对软件特性的失效,导出对应用逻辑软件进行功能安全分析需要考察的要点,有助于把握应用软件的功能安全共性,进而有针对性地寻找软件中的安全薄弱环节并进行改进。所总结出的分析要点,可作为安全关键可编程产品制造商开展规范化、流程化的软件功能安全分析业务的基础。

The safety - critical programmable system is a type of equipment that plays a fundamental role in the safety - critical industri- al applications. It is necessary to conduct functional safety analysis against its application （logic） software to guarantee the functionality of the whole safety- critical programmable system to reach the domain- requested safety integrity level. However, the diversity of ap- plication software brings difficulty to the conduction of the related safety analysis with a high quality. In this paper, the basic structure of the safety - critical programmable system and the features of the software within it are analyzed, and then the key factors for the func- tional safety analysis against the application software within such system are proposed on the basis of failure of such features. The gen- eralization of such key points brings benefit for understanding the common factors that affect the functional safety of the application soft- ware to be analyzed, and thus the weakness within such software can be discovered and resolved with more effectiveness. The achieve- ment of this paper can also be applied as a guidance for the manufacturers of the safety - critical programmable system products to es- tablish a normalized and procedural functional safety analysis against the safety -critical software.