How many parts are there in IEC 61508?

In the field of industrial automation and control systems, the International Electrotechnical Commission (IEC) has developed a set of internationally recognized standards. One of the most important standards in this field is IEC 61508, which deals with the functional safety of electrical, electronic, and programmable electronic safety-related systems. This article aims to give an easy-to-understand overview of the different parts that make up IEC 61508.

Part 1: General requirements

The first part of IEC 61508 sets out the overall framework and general requirements for achieving functional safety in safety-related systems. It introduces the concept of Safety Integrity Levels (SIL), which are a measure of the reliability required for a system to perform its safety functions. This part also defines terms and definitions used throughout the standard, making it a crucial foundation for understanding the subsequent parts.

Part 2: Requirements for electrical/ electronic / programmable electronic related systems

This part of IEC 61508 provides more specific requirements for the design and development of electrical, electronic, and programmable electronic safety-related systems. It covers topics such as hardware and software requirements, safety management, and verification and validation techniques. Part 2 emphasizes the need for systematic and rigorous approaches to ensure the safety and reliability of these systems.

Part 3: Software requirements

Software plays a critical role in many safety-related systems, and therefore, it requires special attention. Part 3 focuses on the requirements and recommendations for software development within the context of functional safety. It addresses topics such as software lifecycle, software architectural design, and software testing. Compliance with the guidelines outlined in this part ensures the quality and dependability of safety-related software.

Part 4: Definitions and abbreviations

The final part of IEC 61508 contains a comprehensive list of definitions and abbreviations used throughout the standard. It serves as a quick reference guide to clarify any technical terminologies encountered while reading and implementing IEC 61508. As a highly technical document, having this handy list facilitates better understanding and interpretation of the various parts and requirements specified in the standard.

In conclusion, IEC 61508 is divided into several parts, each addressing specific aspects related to functional safety in electrical, electronic, and programmable electronic safety-related systems. Part 1 provides an overall framework, while Parts 2 and 3 delve into more detailed requirements for hardware and software development. Finally, Part 4 serves as a valuable glossary for anyone navigating through the standard. Familiarizing oneself with these different parts is crucial for ensuring compliance and achieving functional safety in industrial automation and control systems.