What is the difference between IEC 61508 and 13849 ?

IEC 61508 and EN 13849 are both international standards that aim to ensure the safety of control systems in various industrial applications. However, their scope and application differ significantly.

IEC 61508 is a European standard that applies to a wide range of industries and sectors, including machinery, vehicles, and aerospace. It provides guidance on assessing the performance and reliability of safety-related parts of control systems, using performance levels to determine the required level of risk reduction achieved by the safety functions implemented in the system.

On the other hand, EN 13849 is primarily focused on safety-related control systems employed in machinery, such as electrical, mechanical, and control systems. It provides guidance on the assessment of the risks associated with machinery and the implementation of safety functions to reduce those risks.

The application of the two standards also differs. IEC 61508 is applicable to various industries and sectors, including machinery, vehicles, and aerospace, while EN 13849 is primarily focused on machinery.

Approach to Risk Assessment

Another significant difference between IEC 61508 and EN 13849 is the approach to risk assessment. IEC 61508 adopts a quantitative approach by calculating the probability of failure and considering factors such as diagnostic coverage and safety integrity level. In contrast, EN 13849 follows a qualitative approach, using performance levels to determine the level of risk reduction without quantifying it in numerical terms.

EN 13849 provides guidance on the use of safety-related functions, such as emergency stops, interlocks, and safety monitoring systems, to assess the risks associated with machinery. It also emphasizes the importance of documentation and record-keeping to ensure that safety functions are implemented and monitored effectively.

Conclusion

In conclusion, IEC 61508 and EN 13849 are both important safety standards that provide guidance on the assessment and implementation of safety-related functions in various industrial applications. While both standards are applicable to different industries and sectors, their scope and application differ significantly. IEC 61508 is broader in scope and focuses on the overall performance and reliability of safety-related systems, while EN 13849 is more focused on the assessment of risks associated with machinery. Both standards are essential for ensuring the safety of control systems in various industrial applications.