IEC 61508 is an international standard that governs the functional safety of electrical, electronic, and programmable electronic safety-related systems. First published in 1998 and updated in subsequent years, this standard provides a framework for ensuring that systems can perform safely and reliably, even in the event of faults. It addresses the entire safety lifecycle, from the initial concept to decommissioning, and outlines critical processes such as risk assessment, design principles, testing, and maintenance.

    The standard defines Safety Integrity Levels (SIL), which categorize the required reliability and safety performance of a system based on its application and associated risks. The higher the SIL, the more reliable the system must be, thus necessitating robust engineering practices throughout its lifecycle.