exida explains Blog

Entries tagged with: SIL

  • by Dr. William Goble, CFSE
  • Thursday, January 12, 2012
  • News

2011…A Year in Review

Babies, Bathwater, and Australian Safety Laws

The old saying goes, “Don’t throw the baby out with the bathwater.” But it looks like a number of people in Australia may be in danger of doing just that with their response to the country’s newly harmonized health and safety laws.

Australia’s new Read More...

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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  • 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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  • by Dr. William Goble, CFSE
  • Thursday, May 12, 2011
  • Certification

Buy Certified Equipment, Meet the Standard, Right? WRONG!

  • by Iwan van Beurden, CFSE
  • Thursday, March 21, 2013
  • Software

Changing the PVST Interval. Hey, my Architectural Constraints changed!

Close Enough? Not so Much

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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Do you believe the numbers?

In a couple of recent projects and discussions, I have come across something extremely concerning. Engineers are very good at performing accurate calculations, and the PFDavg and PFH computations for SIL performance verification are improving in precision all the time. Unfortunately, there is often such a focus…

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Functional Safety, Cybersecurity, and Alarm Management in 2013
  • by Dr. William Goble, CFSE
  • Friday, January 10, 2014
  • Certification

Functional Safety, Cybersecurity, and Alarm Management in 2013

2013 was a good year for functional safety progress.  exida Certification issued a record number of new product functional safety certifications in mostly every product category - valves, actuators, solenoid valves, PLCs, fire and gas sensors, process sensors, and components.  The component category is one of the most…

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Getting Good Proof Test Coverage Numbers

Getting Good Proof Test Coverage Numbers

Several years ago we recognized that proof test coverage was an important variable that must be considered when doing PFDavg calculations. We ran some models and discovered that the difference between “perfect” proof test coverage (100%) and a very good 90% could mean a whole SIL

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How can I improve my SIL?

How can I improve my SIL?

Click here to read the first entry in this blog series (What is SIL compliance?)

Click here to read the second entry in this blog series (How is SIL Used?)

As we now know, a Safety Integrity Level (SIL) can only be given to a…

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How is SIL Used?
  • by Loren Stewart, CFSP
  • Tuesday, September 22, 2015
  • Certification

How is SIL Used?

Click here to read the first entry in this blog series 

Once the Safety Integrety Level (SIL) of a product is found, it will be used FOUR ways:

  1. To establish risk reduction requirements
  2. Probabilistic limits for hardware random failure
  3. Architectural constraints 
  4. Read More...

How to Decode an exida IEC 61508 Certificate: Part 2

Click here to read Part 1

Now that you know the step-by-step process of product certification, now let’s take a look at the actual information on the certificate. 

In the left panel (gray background) you will find an exida certification logo. …

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Lifecycle Analysis: It’s Worth the Effort

Obtaining My CFSE/CFSP Certification: Why Bother?

It’s an interesting question and one I asked myself.  For any engineer and/or professional working in the controls business or process industries where safety-related equipment is required, it is essential (per IEC61511-1 Clause 5.2.2: Organization and Resources) to prove competency to carry out any safety-lifecycle activities.  So what does…

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PHA to LOPA: Part II

In some cases the screening methods will indicate that a SIF is needed. These screening methods can be designed to determine how many orders of magnitude risk reduction is needed, allowing a required SIL to be documented for a particular SIF. The screening…

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So what does Interference-Free mean?  And why do we care?

So what does Interference-Free mean?  And why do we care?

An Interference-Free component, either as an interface or a defined functional area, is a system component that is neither safety critical (C3) nor safety relevant (C2), but interfaces with such subsystems. 

If a component has been shown to be interference free (C1), then it has been demonstrated that no…

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  • by John Yozallinas, CFSE
  • Thursday, April 14, 2011
  • Certification

Stepping stones to SIL 3

Imagine.  Marketing has just approached the engineering department and says your new safety product must have SIL 3 Capable certification instead of SIL 2 to be successful.  You are in the engineering group developing this new product.  Now what?

Let’s assume that the “change request” makes…

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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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  • by Dr. William Goble, CFSE
  • Friday, March 04, 2011
  • Certification

Tales from the Certification Wars - Proven In Use versus Certification