- by Denise Chastain Knight, P.E., CFSE, CCPSC
- Wednesday, May 27, 2015
- Functional Safety
Close Enough? Not so Much
Performing a SIL Verification calculation on preliminary design information can be a very useful tool to dial in the Safety Instrumented Function (SIF), Safety Requirements Specification (SRS) content , and define critical elements for the field component purchase specifications. Conceptual verification is typically performed quickly with general design information.…
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- by Chris O'Brien, CFSE
- Thursday, June 07, 2018
- Functional Safety
Functional Safety Assessment of Valve Assemblies (Part 2)
In Part 1, I covered the emerging trends in the valve assembly market, how these trends relate to IEC 61511 requirements, and the anatomy of final elements.
Now let’s discuss why we need to show requirements traceability down through the design of the safety instrumented function and then…
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- by Dr. William Goble, CFSE
- Monday, July 20, 2015
- Certification
Getting Realistic Failure Rate Data - Part 5
Over the course of several blogs , I will talk about getting realistic failure rate data, where this failure data comes from, and how different methods of failure data analysis compare. I think if you understand this, you will begin to get a very good feel of what it…
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- by Denise Chastain Knight, P.E., CFSE, CCPSC
- Thursday, August 27, 2015
- Certification
The Architectural Constraint Blind Side
I did my homework, purchased certified devices, and specified physical redundancy. I expected an uneventful SIL Verification but the assessor is telling me that I have functions failing Architectural Constraints in the sensor and final element groups. How can that be?
Low demand mode Safety Instrumented Function (SIF)…
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- by John Yozallinas, CFSE
- Thursday, October 26, 2017
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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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- by Iwan van Beurden, CFSE
- Monday, June 16, 2014
- Certification
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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- by Ted Stewart, CFSP, exidaCSP
- Tuesday, November 12, 2013
- Certification
You Have Been Endorsed
When current Certified Functional Safety Professionals and Experts (CFSP/CFSEs) come to us seeking further education, we commonly point them to the recently established CFSE Endorsement Program. However, we are often posed questions in return:
- What’s an Endorsement program?
- Is there a test involved?
- If…
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