exida explains Blog

Are You Undertaking Periodic Personnel Performance Assessments?

Are You Undertaking Periodic Personnel Performance Assessments?

One of the changes that was made in 2016 to the IEC 61511 standard was the inclusion of periodic personnel assessments (clause 5.2.2.3), whereby a procedure is required to manage the competence of all those involved in the SIS lifecycle; “periodic” assessments are to be carried out to document…

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Does Your Burner Management System Meet Your Tolerable Risk?

Does Your Burner Management System Meet Your Tolerable Risk?

My previous blog mentioned the fact that a Burner Management System (BMS) is unique, in that this instrumented layer is the last line of defense and may be the only protection layer in the case of a BPCS failure.

Have you ever performed an analysis to determine…

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Hazard Analysis and Risk Assessment of Collaborative Robotic Systems

Hazard Analysis and Risk Assessment of Collaborative Robotic Systems

The world of collaborative robots, or cobots, is making headway. According to a recent report by the International Federation of Robots (IFR), along with Loup Ventures, global robotics spending will reach $13 billion in 2025. Currently, collaborative robots only make up about 3% of all robot sales. This number…

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Is It Possible to Extend Proof Test Intervals?

Is It Possible to Extend Proof Test Intervals?

I am often asked whether extending proof test intervals will be a problem. 

This is a tricky question. The design and engineering SIL calculations for the Safety Instrumented Functions (SIFs) are taking credit for a specific proof test interval with a defined level of coverage, as defined within the…

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Functional Safety Assessment of Valve Assemblies (Part 3)

Functional Safety Assessment of Valve Assemblies (Part 3)

In Part 1, we covered the emerging trends in the valve assembly market, how these trends relate to IEC 61511 requirements, and the anatomy of final elements. In Part 2, we discussed the need to show requirements traceability down through the design of the safety instrumented function…

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Burner Management Systems (BMS) and IEC 61511

Burner Management Systems (BMS) and IEC 61511

Prescriptive BMS standards contain a wealth of knowledge on combustion hazards, unit sequence of operation, and the equipment configuration required for combustion safeguards and combustion control. This experience cannot be overlooked; there is just not a Safety Lifecycle to tie in the Functional Safety Management of the BMS.

That…

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Fake Fact: Diagnostics are useless

Fake Fact: Diagnostics are useless

The idea that diagnostics are useless contradicts everything I’ve ever learned and taught about diagnostics. 

Diagnostics help identify problems. Diagnostics can turn a fault that is unrevealed during normal operation into a detected fault, which allows me to take action. That action could be an automatic transition to the…

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Functional Safety Assessment of Valve Assemblies (Part 2)

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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Do You Measure the Performance of Your SIS?

Do You Measure the Performance of Your SIS?

It always amazes me that when teaching our FSE 100 Functional Safety Engineering course, the number of times I find that end users in the class are not really measuring the performance of their SIS. In most cases, they are doing some measurements, but not thoroughly.

It…

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Does Everyone Really Ignore Failure Rates?

Does Everyone Really Ignore Failure Rates?

While discussing functional safety certification of an integrated valve assembly with a manufacturer, exida stated that all devices (actuator, pneumatic parts, valve, etc.) must be IEC 61508 certified. The manufacturer said this was no problem, and provided a set of exida and TÜV certificates. 

Of…

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Fake Fact: IEC 61508 Does Not Affect Me As an End User

Fake Fact: IEC 61508 Does Not Affect Me As an End User

Though this is largely true, I want to discourage people from completely ignoring the good things that IEC 61508 does for the end user.

IEC 61511 is the process industry functional safety standard derived from IEC 61508. In the very first section of IEC 61511 (“Scope”), the standard describes…

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MISRA Compliance Static Analysis Results for a Real-world Automotive Project

MISRA Compliance Static Analysis Results for a Real-world Automotive Project

Splint is offering to present a “special reward” to the “first person to produce a real program that produces no errors with strict checking.” Here’s a summary of a recent real-world automotive project attempting this.  

TL;DR: We were not successful, but we learned a few things about MISRA compliance. Feel free to skip to the Observations section to learn more. 

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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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Dreaming of a Better Tomorrow?

Dreaming of a Better Tomorrow?

When I was a kid, I liked watching the Jetsons.  I felt certain that by the year 2000 we’d all be enjoying those flying saucers and futuristic homes.  Imagine my disappointment that in 2018 we still drive on 4 wheels… and my home cannot elevate itself above bad weather……

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Fake Fact: Final Elements should not be included in SIF evaluation

Fake Fact: Final Elements should not be included in SIF evaluation

Ehh… If your safety action is stopping flow/closing a valve, how are you going to accomplish this if you consider that the remote actuated valve is not part of your SIF ?

So, what is this myth based on? The title of IEC 61508 reads “Functional safety of electrical/electronic/programmable…

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