exida explains Blog

Entries tagged with: SIF

The Site Safety Challenge – Do You Follow Good Site Practices?

The Site Safety Challenge – Do You Follow Good Site Practices?

The question of whether companies follow good site safety practices is an interesting one. Firstly, what do we mean by good site safety practices?  I think most companies believe they follow good site safety practices but do they really? Are they really measuring and tracking this?

The basis of having good site…

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Too Good to be True

A.K.A You’re About to Severely Under-Design your SIF and Put your People at Risk. Twice this week alone, and much more often than I like to remember, I’ve had safety system designers blindly follow certificates that contain data that simply cannot be true. They get a certificate from…

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What is Systematic vs. Random Capability?
  • by Loren Stewart, CFSE
  • Tuesday, September 01, 2015
  • Certification

What is Systematic vs. Random Capability?

There seems to be a bunch of confusion surrounding systematic capability and random capability.  I will try to clear up the confusion by explaining what is all considered and what the IEC standard says about both. 

Systematic Capability

  • Development process/quality system requirements depend on certification SIL level, higher…

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What’s Your Biggest Fear?
  • by John Yozallinas, CFSE
  • Friday, September 11, 2015
  • Certification

What’s Your Biggest Fear?

Plane crash?

Earthquake?

Ebola outbreak?

Shark attack?

There are probably lots more things to add to that list.  What could we do to prevent them?  Not too much for some… a little more for others.  But would those mitigations be practical?  What tolerable risk can we accept for these…

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Where Do You Stand with Functional Safety?
  • by Loren Stewart, CFSE
  • Thursday, February 21, 2019

Where Do You Stand with Functional Safety?

This year, make your New Year’s resolution safety! 

Take a moment this year and think about where you currently stand with functional safety. And actually, be honest with yourself. REALLY honest. Do you proof test on time, or does it sometimes get pushed out? Do you pull your devices…

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Who gives exida the authority to publish SILSafeData?
  • by Dr. William Goble, CFSE
  • Thursday, January 24, 2019
  • Certification

Who gives exida the authority to publish SILSafeData?

SILSafe Data

SILSafeData contains upper and lower bound ranges of dangerous undetected failure rates for many automation devices. It was created by exida using statistical analysis of FMEDA failure rate predictions. The component database used in the FMEDAx tool is based on…

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Why Proof Test Coverage Is So Important For A SIF to Achieve Its Target SIL?

Why Proof Test Coverage Is So Important For A SIF to Achieve Its Target SIL?

This is a question I often get asked when I’m teaching our FSE100 course on Functional Safety, when we discuss the purpose of Proof Testing and coverage.  It’s amazing how many end users assume perfect proof testing (i.e. 100% coverage), that is capable of finding, all the…

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Why should I get my mechanical device certified per IEC 61508?

I was recently approached with a question regarding why it would be necessary to certify mechanical devices, such as valves, per IEC 61508 when it is not clearly stated in the standard that the standard is applicable to such devices.  After looking through IEC 61511 and Read More...

World Cup Fever & Failure Rates

World Cup Fever & Failure Rates

Do you have World Cup Fever? Well I do. Especially after the Netherlands (Holland) beat Spain 5-1 on Friday. I wished that was the score last time they played. So what does this have to do with failure rates? Sometimes my mind works in odd ways. While driving home…

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