exida explains Blog

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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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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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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I saw and responded to a LinkedIn discussion on this very issue, where someone had asked “if I have a misaligned limit switch that fails dangerously, then is it random or systematic? “.  This is an intriguing question because many view human error as being systematic and, whereas, this…

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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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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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It’s hard to believe that the IEC61511 standard has been in existence since 2003, and most companies operating in the process, chemical, and refining industries (or any other hazardous process manufacturer) have adopted its practices.  It’s also significant that any plants that were built back then with a…

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The Safety Integrety Level (SIL) of a product is determined by three things:

1. The Systematic Capability Rating
2. The  Architectural Constraints for the element
3. The PFDavg Calculation for the product

The Systematic Capability Rating

Systematic Capability is established by having your quality management system audited per IEC 61508.…

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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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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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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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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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