exida explains Blog

Entries tagged with: SIL Verification

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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Still Using Excel to do PFD Calculations?
  • by Steve Gandy, CFSP
  • Monday, April 28, 2014
  • Software

Still Using Excel to do PFD Calculations?

It’s very interesting to me to find that people are still using excel to do PFD calculations.  Whereas this is probably okay for simple single element architectures (i.e. single sensor, single logic solver and single final element), it becomes extremely complicated when dealing with redundant architectures.  Moreover, for performing…

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To Spreadsheet…or NOT to Spreadsheet
  • by Dr. William Goble, CFSE
  • Thursday, September 03, 2015
  • Software

To Spreadsheet…or NOT to Spreadsheet

I remember the first time I ever saw a spreadsheet program. It was called “VisiCalc" and ran on a Commodore PET computer. My first thought was, “What is that good for?” Then I tried it and was totally hooked. I conclude that the creation of the spreadsheet has changed…

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Which FSAs Do I Have to Perform?

Which FSAs Do I Have to Perform?

The new release of IEC61511:2016 has caused some confusion when it comes to the Functional Safety Assessments (FSAs). Which ones are mandatory?

The confusion comes from the wording in the standard and the clarifications in the notes. The relevant clause in the standard 5.2.6.1.4 states:

A FSA team…

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Why Run-to-Fail Is Not A Good Maintenance Strategy For SIS

Why Run-to-Fail Is Not A Good Maintenance Strategy For SIS