What is the difference between IEC 61511 and IEC 61508 ?

IEC 61511 is an application-specific standard that builds upon the foundation of IEC 61508, while IEC 61508 is a general standard that applies to various industries. IEC 61511 focuses on functional safety in the process industry, which includes sectors such as oil and gas, chemical, and pharmaceutical manufacturing. It provides detailed guidance on how to apply the principles and requirements of IEC 61508 to process industry safety systems.

Whereas IEC 61508 is a broad standard applicable to various industries, IEC 61511 is focused specifically on the process industry sector. It addresses the specific challenges associated with process industry applications, such as the need for continuous operation, large-scale infrastructure, and complex control systems.

One major difference is the scope of application. IEC 61508 is a general standard that applies to various industries, whereas IEC 61511 specifically addresses the requirements for functional safety in the process industry.

IEC 61511 provides guidance on the design, implementation, operation, and maintenance of safety instrumented systems (SIS) used to mitigate risks in the process industry. It also covers topics like hazard identification, risk assessment, safety requirements specification, and the design and implementation of safety instrumented systems (SIS).

In summary, IEC 61511 is a sector-specific standard that provides detailed guidance on the application of functional safety principles and requirements in the process industry. It focuses on the design, implementation, operation, and maintenance of safety instrumented systems (SIS) used to mitigate risks in this sector.