exida explains Blog

Entries tagged with: IEC 61508

  • by Dave Butler, CFSE
  • Wednesday, July 10, 2013
  • Software

Tracing and Validation Test Planning

Please see the first entry of the Requirements Management blog series here

Please see the second entry of the Requirements Management blog series here

So, you have a set of detailed safety requirements.  You have derived them down to a level of detail you feel spells out…

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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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What do you need to know about traceability for IEC 61508?
  • by John Yozallinas, CFSE
  • Thursday, October 26, 2017

What do you need to know about traceability for IEC 61508?

Traceability is about connecting the dots to determine that the web of activities for a functional safety project have followed the proper paths.  Think of it like cheating at hide-n-seek; it provides a shortcut to find all those requirements and design parts that are hidden in your specification documents. …

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What Good is a Safety Manual?

What Good is a Safety Manual?

Many products have options and features that are valuable to users.  But not all these features should be permitted while the product is performing a safety function.  For example, HART communications should not be permitted to write data to a transmitter while it’s performing the safety function.  If you…

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What is a “House Certificate?”
  • by Dr. William Goble, CFSE
  • Tuesday, March 11, 2014
  • Certification

What is a “House Certificate?”

exida was recently auditing a systems level project per IEC 61511.  During such audits we check to verify that all equipment used in a safety instrumented function meets systematic capability by either IEC 61508 certification OR justification per reasonable IEC 61511 “prior use” criteria.  Most engineers at…

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What is Competency Anyway?

What is Competency Anyway?

I’ve been following some discussions from one of the online forums regarding competency and it’s clear from the correspondence that the issue of competency is still very subjective.  It made me think about “what is competency?” To me it’s a blend of knowledge and experience and just how well…

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When is a Variable Frequency Drive a SIS?

It used to be that a pump would operate at a single speed dictated by a motor, thus fixing the pump curve. As the discharge flow decreased due to a restriction downstream, the pump outlet pressure would increase reaching its deadhead pressure. If the downstream piping and vessels were…

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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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Which Edition of IEC 61508 is Relevant to Me?

Simply stated, the 2nd edition of IEC 61508 is the relevant standard for newly developed products and new certifications.  This represents the current best practices on functional safety techniques and measures, and is what the marketplace expects for today’s products. 

Renewed certifications can use the 1st edition of…

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Who needs sliced bread?  We’ve got ARCHx!
  • by John Yozallinas, CFSE
  • Tuesday, December 04, 2018
  • Software

Who needs sliced bread?  We’ve got ARCHx!

I’ve heard this phrase so many times in my life… “<Something> is the best thing since sliced bread.” I personally can’t remember a time when sliced bread was not available, but I certainly remember going to the deli and having them use the slicing machine before handing me a bag…

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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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  • by Iwan van Beurden, CFSE
  • Tuesday, January 17, 2012
  • Certification

Why am I not on “the list?”

Why Do We Need You?

This was a question posed to me by an engineering contractor the other day.  Although I found the question quite strange, it made me think “okay, why do they need us?”  I suppose there are a few answers:

  1. Regarding the end user perspective, we exist to provide an independent third-party…

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Why Does My Risk Assessment Require an FMEDA?

Why Does My Risk Assessment Require an FMEDA?

If you find yourself faced with this question you might be wondering why it is that having successfully used risk assessments without FMEDA your team are suddenly faced with the complexity of executing FMEDAs.

Maybe us safety people answer with a follow…

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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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  • by Ted Stewart, CFSP, exidaCSP
  • Friday, February 22, 2013
  • Certification

Why Personnel Functional Safety Certification Programs are Needed

The publication of the international functional safety standards IEC 61508 (1999), IEC 61511 / ISA-84 (2004) and IEC 62061 (2005) were significant milestones in the effort to increase equipment and process safety. 1,2,3  Unfortunately, the release of safety standards does not by itself make the world a safer place.…

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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...

You Need a Checklist!

You Need a Checklist!

At least I do.  Sometimes I wonder how I could forget certain things.  Maybe it’s age? Maybe it’s information overload?  It’s always apparent when I get ready to go on vacation.  You’ve probably been in the same situation… arriving at your destination only to find that the one thing…

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