In industrial safety, Safety Instrumented Systems (SIS) are crucial for protecting processes from hazards. However, one area that often causes confusion is how human and systematic failures are addressed in comparison to random hardware failures. The IEC 61511 standard provides valuable guidance on this distinction, helping organizations ensure compliance and maintain safety integrity.
Human vs. Hardware Failures
The IEC 61511 Approach While random hardware failures can be quantified using the Probability of Failure on Demand (PFD) metric, human and systematic failures are not captured by these calculations. Attempting to apply PFD calculations to human failures often leads to misguided solutions—such as increasing redundancy or testing—that may exacerbate the issue. This is where IEC 61511 takes a different approach. Human and systematic errors typically arise from flaws in processes, designs, or execution. Unlike hardware failures, which can be addressed through reliability data and redundancy, these errors require a more qualitative approach. IEC 61511 emphasizes that administrative controls—rather than hardware-based solutions—are key to managing these risks.
Administrative Controls and Functional Safety Planning
IEC 61511’s framework for addressing human and systematic failures focuses on functional safety planning throughout the lifecycle of the SIS, from design to decommissioning. Key activities such as verification, validation, functional safety assessments, and regular audits are essential components of this strategy. These measures are designed to ensure that potential human and systematic errors are identified and mitigated proactively.
Recorded Webinar
To explore these concepts in more detail, this webinar provides an in-depth discussion of how IEC 61511 addresses human and systematic failures, explaining why they are excluded from PFD calculations and how administrative controls play a vital role in reducing their impact. Best practices for implementing these controls will also be shared, helping you align your SIS with compliance requirements while meeting real-world safety demands. Whether you’re a process engineer, safety manager, or functional safety professional, this webinar will equip you with the knowledge and tools to navigate the complexities of human and systematic failures. Don’t miss out on this opportunity to enhance your safety management practices and ensure the effectiveness of your Safety Instrumented Systems.