exida explains Blog

Comparing the IEC 62443 Software Engineering Process to IEC 61508: Where Do They Overlap?

Comparing the IEC 62443 Software Engineering Process to IEC 61508: Where Do They Overlap?

With the appearance of malware and nation state attacks on Industrial Control Systems (ICS), such as the Stuxnet (2010), Industroyer (2016) and TRITON (2017) attacks, the IEC 62433 standards are gaining wider attention.  

While the potential targets to attack in an ICS system are many-fold, one plant asset that…

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Functional Safety Certification Started with Logic Solvers
  • by Dr. William Goble, CFSE
  • Tuesday, November 27, 2018
  • Certification

Functional Safety Certification Started with Logic Solvers

IEC 61508 functional safety certification began in the 1990s. As I recall, the only organizations doing this work in those days were TÜV Rheinland and TÜV Product Services (now TÜV Sud). These two companies remain competitors. 

Functional safety certification started with logic solvers. Some engineers and regulators at the…

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Using SILSafeData to Check Your Failure Data Source
  • by Dr. William Goble, CFSE
  • Monday, October 29, 2018
  • Certification

Using SILSafeData to Check Your Failure Data Source

www.SILSafeData.com is a complimentary resource that contains the upper and lower bounds failure rates for many categories of automation equipment, as well as the methodology used by exida to derive the numbers.  

Many of you have asked how to…

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The New Technology in Logic Solvers
  • by Dr. William Goble, CFSE
  • Thursday, September 27, 2018
  • Certification

The New Technology in Logic Solvers

I heard about a “safety certified” PLC in the late 1980s at an ISA SP84 standard committee meeting. The “logic solver” (as they later called it) was the focus of attention in the field of functional safety back then. Many engineers even said, “My system is safe because I…

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Do you know your Site Safety Index?
  • by John Yozallinas, CFSE
  • Thursday, August 02, 2018
  • Certification

Do you know your Site Safety Index?

There’s a lot that exida does behind the scenes to advance the industry and benefit you. We try to make sense of data that we collect and put it to good use. One thing we found is that human activities play a role in functional safety, often causing the intended safety performance…

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Functional Safety Assessment of Valve Assemblies  (Part 1)

Functional Safety Assessment of Valve Assemblies (Part 1)

In this blog series, I will cover the emerging trends in the valve assembly market, how these trends relate to the IEC 61511 requirements, and what's in a final element. When you look at the different devices that go into some of these safety systems, the final element becomes…

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Why is Safety Certification So Tough?
  • by John Yozallinas, CFSE
  • Thursday, January 04, 2018
  • Certification

Why is Safety Certification So Tough?

Some organizations complain about the ‘high bar’ to comply with 61508.  They complain that there is too much overhead in documentation and testing, and it all costs too much.  Other organizations actually benefit from this ‘high bar’ as a barrier to entry for competitors.  This is a differentiation factor…

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IEC 61508 Functional Safety Certificates - To Accept or not to Accept?
  • by Dr. William Goble, CFSE
  • Thursday, August 10, 2017
  • Certification

IEC 61508 Functional Safety Certificates - To Accept or not to Accept?

I get an email that includes a “certificate” of some sort most every week.  The sender asks “Can I accept this certificate?”  Or the sender might ask “Are these failure rates valid for the process industries?” 

At exida we have some specific criteria we use when performing third party…

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Tales from the Certification Wars - Proven In Use versus Certification
  • by Dr. William Goble, CFSE
  • Wednesday, April 19, 2017
  • Certification

Tales from the Certification Wars - Proven In Use versus Certification

Knowing Scope of Work (SOW)

Knowing Scope of Work (SOW)

There was a joke I heard many years ago that went like this…

3 workers were hired to run telephone lines.  The first part of their job was to install the poles on which the wires would run.  Each day, the foreman would ask the workers how many poles…

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High Demand Diagnostic Credit?
  • by Dr. William Goble, CFSE
  • Thursday, January 19, 2017
  • Certification

High Demand Diagnostic Credit?

The IEC 61508 standard states that automatic diagnostics can only lower the dangerous undetected failure rate if those diagnostics execute 100 times faster than the expected demand rate.  That requirement has always seemed excessive to many of us here at exida.  As an accredited Certification Body we…

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The 3rd Party Effect (Part 1)

The 3rd Party Effect (Part 1)

Have you even wondered, been involved, or WERE the little kid that didn’t listen to your parents, but always listened to a teacher?  This is called the “Third party effect.”  In business, it is well known that the power of persuasion can be the most effective by a third…

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Welcome to my world
  • by John Yozallinas, CFSE
  • Sunday, October 02, 2016
  • Certification

Welcome to my world

Sure, you might think I’ve got it made… sitting here on my perch telling you what you need to do to meet IEC 61508, while you sit there with all the work to do.  Well, it wasn’t always that way.  I was in your shoes, responsible for achieving functional…

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FMEDA Predictions
  • by Loren Stewart, CFSE
  • Thursday, September 01, 2016
  • Certification

FMEDA Predictions

The FMEDA technique is performed on a specific device (e.g., ball valve, pressure transmitter, temperature sensor, electronic module, etc.) specified down to the manufacturer and series/model. Based on the specifics of the design, the parts used to execute the design, the design margins, any automatic diagnostics, the…

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Who’s Driving Your Process?
  • by John Yozallinas, CFSE
  • Thursday, August 18, 2016
  • Certification

Who’s Driving Your Process?

When I start working with new customers for IEC 61508 certification projects, it’s easy to understand why they might not have a compliant development process for functional safety:  they’ve never done it before!  They understand their market and their products, but they need help to understand the…

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