Many functional safety professionals fall into the "Numbers Trap," assuming that meeting a PFDavg (or PFH for High/Continuous mode) PFH target automatically guarantees SIL compliance. However, achieving a truly safe and compliant Safety Instrumented Function (SIF) requires much more than just a passing mathematical probability.
In this webinar, we break down the three mandatory performance criteria mandated by IEC 61511 and IEC 61508. We will explore why the SIL achieved is only as strong as its weakest link and how ignoring architectural constraints or systematic capability can lead to over-designed capital expenses or, worse, hidden operational risks.
Key Discussion Points:
- The Three Barriers: A deep dive into Probabilistic Performance (PFDavg/PFH), Minimum Architectural Constraints (HFT), and Systematic Capability.
- Hardware Fault Tolerance (HFT): Navigating the complexities of Route 1H vs. Route 2H and understanding how equipment selection impacts your redundancy requirements.
- The SIDA Requirements: How to ensure your SIF functions as a truly Independent Protection Layer (Specific, Independent, Dependable, and Auditable).
- Use of Realistic Failure Data: How to verify that the failure rate data you are using is credibale and realistic
- Avoiding the Pitfalls: How to prevent nuisance trips and operational burdens through correct SIL Verification.
Join us to learn how to move beyond simple calculations toward a holistic, compliant, and defensible safety lifecycle.
Todd Stauffer, PE, is responsible for exida’s alarm management products and services (training, consulting, SILAlarm™ rationalization software). He has been an editor and voting member of the ISA-18.2 standards committee on alarm management since 2005. He was an active participant in the development / publication of the ISA-18.2 standard itself and as an editor / reviewer for ISA’s series of technical reports on alarm management (including ISA-18.2 TR1 “Alarm Philosophy” and TR3 “Basic Alarm Design” for which he served as co-chair). He is currently the co-chair of the joint working group developing ISA-84.91.03 “Functional Safety of Safety Controls, Alarms, and Interlocks for the Process Sector”. Todd is an instructor for ISA’s official training class on alarm management and is exida’s representative on the EEMUA 191 committee.
He has executed numerous alarm philosophy workshops, gap assessments, and alarm management training classes for different control system platforms. Todd developed exida’s alarm philosophy best practices template. He is also the product manager for the SILAlarm rationalization software tool. Todd is an industry thought leader in alarm management. He has published numerous articles and presented many papers at supplier user group and industry conferences. His presentations have garnered three “Best in Conference” nominations and his article “Don’t be Alarmed: Avoid Unplanned downtime from alarm overload“ was selected as Intech magazine’s best article of the year in 2007.