Failure Rates in Functional Safety: A Practical Guide for Working Engineers
Failure rates are central to SIL verification, device selection, diagnostics, and proof testing. This guide explains λDU, λDD, λSU, and λSD, where the values come from, and how functional safety…
How to Apply the Beta Factor: A Practical Guide to Common Cause Failures in SIL Verification
Learn how to apply the beta factor (β) in SIL verification and understand its link to common cause failures. This guide walks through where β values come from, how they…
Spurious Trip Rate Explained: 6 Facts Every Functional Safety Engineer Should Know
Spurious Trip Rate (STR) is often overlooked in functional safety. Learn what STR is, how it’s calculated, and why balancing STR with PFDavg matters.
How to Use Proof Test Coverage (Cpt) to Improve PFDavg
Proof test coverage (Cpt) plays a major role in determining whether a SIF meets its target SIL. This article explains what Cpt is, how it affects PFDavg, and how even…
How MTTR Affects Your SIL Calculations: A Beginner’s Guide to Mean Time to Restore
Learn how MTTR (Mean Time to Restore) fits into PFDavg and STR in IEC 61511 compliance. A clear, beginner-friendly guide for functional safety.
PFDavg Explained: 6 Essentials for Getting Started with SIL Calculations
This beginner-friendly guide explains what PFDavg (Probability of Failure on Demand) means in functional safety, how it's calculated, and why it matters under IEC 61511. With clear examples, key definitions,…
Proof Testing of SIFs: Understanding Its 3 Purposes and Its Importance
Proof testing ensures your Safety Instrumented Functions (SIFs) work when needed by uncovering hidden faults. Learn why proof tests are crucial for lowering PFDavg and maintaining Safety Integrity Level (SIL)…
