The concept of safety integrity level (SIL), safety lifecycle, the qualitative and quantitative methods of the safety integrity level selection, and how to determine the required SIL are discussed.

• 摘要讨论安全完整性水平的概念、安全生命周期、安全完整性水平选择的定性、定量方法，介绍如何遵照功能安全的国际标准进行安全完整性水平选择。