IEC 61511-3:2016 applies when functional safety is achieved using one or more SIF for the protection of either personnel, the general public, or the environment; may be applied in non-safety applications such as asset protection; illustrates typical hazard and risk assessment methods that may be carried out to define the safety functional requirements and SIL of each SIF; illustrates techniques/measures available for determining the required SIL; provides a framework for establishing SIL but does not specify the SIL required for specific applications; does not give examples of determining the requirements for other methods of risk reduction. This second edition cancels and replaces the first edition published in 2003. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: Additional H&RA example(s) and quantitative analysis consideration annexes are provided.