What is BS EN 61508?

BS EN 61508, also known as the International Electrotechnical Commission (IEC) standard IEC 61508, is a technical international standard for the functional safety of electrical, electronic, and programmable electronic systems. It provides guidelines for the development and assessment of safety-related systems, ensuring that they are designed, implemented, operated, and maintained to achieve the necessary level of safety.

Scope and Objectives

The scope of BS EN 61508 is broad, covering various sectors such as process industries, power generation, transportation, and medical devices. Its primary objective is to prevent and reduce accidents caused by malfunctions in programmable electronic systems. The standard addresses all stages of the system lifecycle, starting from the concept phase through design, development, installation, operation, maintenance, and finally decommissioning.

Key Requirements and Concepts

BS EN 61508 introduces several key requirements and concepts to ensure functional safety. One of the fundamental concepts is the Safety Integrity Level (SIL). SIL is a defined reliability measure that quantifies the performance of a safety function within a system. It ranges from SIL 1 (lowest) to SIL 4 (highest), with each level requiring specific measures to achieve the desired level of safety.

The standard also emphasizes the importance of hazard and risk analysis. A thorough understanding of potential hazards and associated risks is crucial for determining the appropriate safety strategies and measures. This includes identification of failure modes, assessment of their likelihood and consequences, and implementing suitable risk reduction techniques.

Benefits and Challenges

Implementing BS EN 61508 brings several benefits to organizations. It ensures that safety considerations are integrated into the entire system lifecycle, leading to reduced risk of accidents, injuries, and financial losses. Compliance with the standard also enhances an organization's reputation and provides a competitive advantage in the market.

However, implementing BS EN 61508 may pose challenges, especially for organizations that are new to functional safety. It requires expertise in safety engineering, hazard analysis, and system design. Meeting the standard's requirements can be time-consuming and costly, necessitating dedicated resources and thorough documentation.