关键词: 系统Signature, 安全保障系统, 危险失效, 安全失效

Abstract: The safety ensuring system is a system whose failure will cause an enormous life and property loss, and seriously damage environment. Analyzing its function and calculating accurately its indexes can effectively reduce risks and improve the system safety. By using system signature to build mathematics models, this paper defines and solves fail-dangerous(FD)signature and fail-safe(FS)signature, aiming at exploring its function in two modes. Besides, it defines FD and FS probability coefficients, and calculates them when system fails. Finally, this paper gives some examples to show the process of these algorithms.

Key words: system signature, safety ensuring system, fail-dangerous, fail-safe