exida explains Blog

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, CFSP
  • 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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Are All Field Devices Type A?

Are All Field Devices Type A?

I was told by an end user engineer that he considers all field devices to be simple Type A devices.  In IEC 61508, Type A is defined as a device with well-defined failure modes, well known failure rates, and behavior under fault conditions that can be completely determined.  Type…

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Site Safety Index™ (SSI) – A Simple Model for Site Variations in Safety
  • by Dr. William Goble, CFSE
  • Monday, April 11, 2016
  • Certification

Site Safety Index™ (SSI) – A Simple Model for Site Variations in Safety

In several of our technical papers over the years, we have noticed that failure rates for the manufacturer, model number are different at different sites, even when the processes were quite similar.  When I have mentioned this to end users and manufacturers, often the response is “Yes, I have…

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Site Safety Index IMPACT on Failure Rates and PFDavg

Site Safety Index IMPACT on Failure Rates and PFDavg

Performing site audits for numerous customers can be very telling.  All sites have their own unique layout, procedures, documentation, and people.  Did you know that failure rates differ from site to site?  Are you surprised?  According to our recent webinar results, the majority of people aren’t, and in fact…

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A Year in Review: Functional Safety and Cybersecurity in 2015
  • by Dr. William Goble, CFSE
  • Tuesday, January 26, 2016
  • Certification

A Year in Review: Functional Safety and Cybersecurity in 2015

Good things happened in the fields of functional safety and control system cybersecurity in 2015.  I am not going to include the exciting new Star Wars movie as an event in the list as it does not really fit into the topic. But keeping focused, my highlights is 2015…

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WHY are Failures Occurring at a Different Rate from Our Other Site?

WHY are Failures Occurring at a Different Rate from Our Other Site?

Site audits have shown many differences in how things are done from site to site. This impacts many variables in a safety instrumented system!

A key metric for process industry designs is called average Probability of Failure on Demand (PFDavg).  After several studies of many field failure and proof…

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  • by Chris O'Brien, CFSE
  • Thursday, January 07, 2016
  • Certification

Best Practices in Achieving Functional Safety in Turbine Applications - Part 3

The adoption of the functional safety standards continues to gain momentum in turbine applications. Both industrial and power turbine sites are now requiring compliance to IEC 61511. This blog will review both technical requirements and market trends related to functional safety system design. Market trends will cover which standards…

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Best Practices in Achieving Functional Safety in Turbine Applications - Part 1

The adoption of the functional safety standards continues to gain momentum in turbine applications. Both industrial and power turbine sites are now requiring compliance to IEC 61511. This blog will review both technical requirements and market trends related to functional safety system design. Market trends will cover which standards…

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Say What?
  • by John Yozallinas, CFSE
  • Thursday, October 01, 2015
  • Certification

Say What?

The “see something, say something” mantra is being used as a countermeasure for terrorism and crime, but it can also be effective to improve functional safety in development teams and plant sites.  It could be useful in general process improvement as well.

This can be especially evident during training…

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