Safety Instrumented Systems Blog

Uncertainty and Bayesian Inference Video

We are proud to introduce our first SISEngineer.com original video. This video gives a brief non-technical introduction to how Bayesian

Fail Safe Regulators

The humble airset filter regulator does not get a lot of love. Relegated to a lonely corner of the control

Functional Safety for Autonomous Vehicles (Part 3)

Today’s post finally wraps up SIS Engineer’s initial foray into the strange and exotic world of automotive functional safety. In

SIS Survivability and Fire Safety

In my experience, few subjects cause more confusion and misunderstanding in the instrumentation and SIS arena than Fire Safety. Even

Human Error and Systematic Failures

Today I want to highlight an excellent paper “Improving Barrier Effectiveness Using Human Factors Methods” recently published by Mr. Dave

Bayesian Coin Flipping

The following is a quick example illustrating how the Bayesian updating process can be used to update prior knowledge based

Functional Safety for Autonomous Vehicles (Part 2)

In part 1 of this article we introduced the autonomous vehicle functional safety standard, ISO 26262. We discussed its similarities

Functional Safety for Autonomous Vehicles (Part1)

When they are not spontaneously combusting or crashing into parked cars (again, again, and again) autonomous vehicles are the coolest thing

Uncertainty in SIL Calculations

Some time ago, I ran across a complex Safety Instrumented Function (SIF) that had a proof test interval (PTI) of

Getting Started in SIS Cybersecurity (Part 2)

In part 1 of this article, we covered the various standards and guidelines that are available to inform the design

Getting Started in SIS Cybersecurity (Part 1)

Unless you have been living in an underground bunker for the last decade, you are probably aware that cybersecurity for

IEC 61511 is Wrong About Systematic Failures

The other day, a colleague stopped by my office to chat. We talked of the kids, our health, upcoming business

Useful Life, Mission Time, and Proof Tests

I have seen several questions recently in online forums where engineers were unclear about the differences and relationships among useful

Hierarchical Bayesian Prior Use

I presented my paper “A Hierarchical Bayesian Approach to IEC 61511 Prior Use” at the 14th Global Congress on Process

Global Congress on Process Safety – Highlights

The 14th Global Congress on Process Safety (GCPS) was held on April 22-26, 2018 in Orlando, FL. The venue was

When Safety Relays Attack!

It was a dark and stormy night. All was quiet at the operator console, when suddenly the alarm panel lit

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