IEC 61511-0:2018(E) provides an overview of the other three parts of IEC 61511 Functional safety - safety instrumented systems for the process industry sector. There are many hazards in process industries that can lead to loss of containment, resulting in an impact on health, safety, environment and plant assets. Process safety is best achieved by using inherently safe processes. However, when this is not practical or possible, protective systems are required to mitigate the risk of hazards to an acceptable level. There are three parts to this series: IEC 61511-1:2016, Functional safety - Safety instrumented systems for the process industry sector - Part 1: Framework, definitions, system, hardware and application programming requirements IEC 61511-2:2016, Functional safety - Safety instrumented systems for the process industry sector - Part 2: Guidelines for the application of IEC 61511-1:2016 IEC 61511-3:2016, Functional safety - Safety instrumented systems for the process industry sector - Part 3: Guidance for the determination of the required safety integrity levels