exida explains Blog

Entries tagged with: IEC 61508

Fisher Controls

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Functional Safety And Electromagnetic Interference: What’s the Connection?

Functional Safety And Electromagnetic Interference: What’s the Connection?

Functional Safety and Electromagnetic Interference (EMI) may not often be used in the same sentence. But EMI is just one of the environmental stresses that can stop a system from performing its safety function. It is important for a functional safety system to be immune from the EMI levels…

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Functional Safety and Taxes: Are you an expert?

Today, April 15th, is tax-day in the US.  Ok, the Internal Revenue Service (IRS) has given us a few extra days this year (the tax filing deadline is not until April 18th).

There are a lot of similarities between how you do your taxes and how you handle…

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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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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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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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Functional Safety Certification Started with Logic Solvers
  • by Dr. William Goble, CFSE
  • Tuesday, November 27, 2018
  • Certification

Functional Safety Certification Started with Logic Solvers

IEC 61508 functional safety certification began in the 1990s. As I recall, the only organizations doing this work in those days were TÜV Rheinland and TÜV Product Services (now TÜV Sud). These two companies remain competitors. 

Functional safety certification started with logic solvers. Some engineers and regulators at the…

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Functional Safety Evolution

Functional Safety Evolution

Protection systems have been around for a long time, going back to having a canary in the mine, and throughout the Industrial Revolution; so they are not a new thing.  Various stakeholders were involved in business enterprises: owners, suppliers, consumers, community members, and workers. Usually the business owners held…

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Functional Safety Standards - IEC 61508 vs. IEC 61511

Functional Safety Standards - IEC 61508 vs. IEC 61511

IEC 61508 is considered a basic or “umbrella” standard for functional safety.  It is generic and sometimes even vague.  IEC 61508 was intended that various industry sectors provide their own specific standards and guidelines as needed.  Here we can see the relationship between 61508 and other standards, such as…

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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 Realistic Failure Rate Data - Part 1

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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Getting Realistic Failure Rate Data - Part 3

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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High Demand Diagnostic Credit?
  • by Dr. William Goble, CFSE
  • Thursday, January 19, 2017
  • Certification

High Demand Diagnostic Credit?

The IEC 61508 standard states that automatic diagnostics can only lower the dangerous undetected failure rate if those diagnostics execute 100 times faster than the expected demand rate.  That requirement has always seemed excessive to many of us here at exida.  As an accredited Certification Body we…

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  • by Iwan van Beurden, CFSE
  • Tuesday, April 30, 2013
  • Certification

How Do You Certify to IEC 61508?

As you may already know, when it comes to the certification of equipment according to IEC 61508, there are several 3rd party agencies from which to choose. It is obvious from reviewing different assessments on for example a solenoid, that the interpretation of IEC 61508 and thereby the assessment…

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How does CMMI help my safety assessment?

We have CMMI processes at CL3; does that help us get IEC 61508 certification for SIL 3?

Companies that deliver a product or service do so by following a sequence of processes.  High quality deliverables are a result of high quality processes and continuous improvement in…

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How Much Testing Is Enough?

How Much Testing Is Enough?

Have you ever wondered if you tested your product enough? Either in enough ways or for a long enough time?  This assumes that you’d prefer to discover all the problems before your customers do. If you follow a 61508 compliant development process, you should be able to…

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How to Calculate Proof Test Coverage
  • by Dr. William Goble, CFSE
  • Thursday, October 16, 2014
  • Certification

How to Calculate Proof Test Coverage

Most engineers who design and verify safety instrumented functions (SIFs) understand how hard it is to design a manual proof test with high effectiveness (also called high proof test coverage). Those folks who understand that a proof test is not likely to detect all failures never use simplified equations…

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How to Decode an exida IEC 61508 Certificate: Part 1

So you downloaded a product certificate from the exida website and you are trying to understand the information documented in the certificate.  Also, you likely want to know what stands behind the certificate and what was involved in the certification of the product.
 
I’m not…

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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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I have just one more, small change…

How many development teams have heard those few, innocent words uttered from Marketing/Management toward the end of the development phase of a project, only to have their schedule blown out of the water?  The phase of development into which the change is introduced determines the size of the concentric…

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