In the following series of blogs, we'll go back to basics and run down everything you need to know to get started in functional safety. We'll start with some more general terms and descriptions and make our way to more advanced material.

IEC 61508: 2010 International Performance-Based Standard 

The IEC 61508 standard, published by the International Electrotechnical Commission (IEC), consists of methods on how to apply, design, deploy, and maintain automatic protection systems called safety-related systems. 

This IEC standard is the basis for the other more specific industry-based standards that cover functional safety of electrical / electronic / programmable electronic safety-related systems. It entails requirements for suppliers of process control and instrumentation for safety. 

The main objective of IEC 61508 is to create well-designed products that will be used in safety instrumented systems (SIS) by following the overall hardware and software safety lifecycle procedures and by maintaining the associated documentation. 

Fun Facts about IEC 61508:[SF1] [SF2] 

• Applies to all “Automatic Protection Systems” – E/E/PE (electrical / electronic / programmable electronic).
• Also applies to simple mechanical devices, such as final elements.
• Provides measures of protection against “random” hardware failures and “systematic” design failures.
• Contains 4 Normative parts plus 3 “Guideline” parts.
• Can be applied to PROJECT level work—bespoke (turnkey) systems—and PRODUCT level work, off-the-shelf products applied in many applications.
• Defines the concept of SIL & the Safety Lifecycle.
• Known as the umbrella standard since the more specific standards fall under it and are covered by it.
• Is performance-based, not prescriptive like most standards.