Tales from the Certification Wars - Proven In Use versus Certification

There have been passionate debates in email and meetings about “Proven In Use” versus IEC 61508 certification. Most debate characterized these evaluation techniques as competing methods.  In 2000 when IEC 61511 was being written there were few IEC 61508 certified products on the market. The alternative justification technique of “proven in use” was often the only option. Fortunately time brings knowledge and progress. More than decade later, there are hundreds of PLC products, process sensors, and final element products available with IEC 61508 certification (See http://www.sael-online.com).  But a question still remains “Does an IEC 61508 certified product need to be proven in use?”

Safety design is serious. Design mistakes could result in an accident. One must select equipment that…

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Tales from the Certification Wars - Who certifies the certification agency?

I have often heard the question “Who says they can issue a certification?”  This is often accompanied by “Why can’t I certify my own product?”  “Who knows our design better than we do?” Good questions.

The IEC 61508 standard does not require certified products for Functional Safety.  However, competency is required and “independent assessment” is required for higher SIL levels.  So what is happening in the market?

Some companies self-certify their products. I have seen certificates usually signed by their quality manager declaring “Suitable for SIL X,” or such language.  I recently asked about the procedure used. This particular manufacturer spoke with a few dozen of their customers and asked if the product was working well.  One had been designing…

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Counterfeit Certificate!

I am told that plagiarism is a compliment. Since exida is the leading company for IEC 61508 certifications I suppose it was bound to happen. Well it did. exida got an email from our sales representative in China. He asked why this certificate was not listed on the exida Safety Automation Equipment List. An electronic copy of the certificate was sent to me. It was easy to spot that the certificate was forged. Looking closely I see they did a good job. The fonts and spacing were pretty good. But I recognized that this particular certificate was from another customer, Virgo. Virgo has gone through the effort of having their engineering process and manufacturing process audited and inspected. They demonstrated…

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Why am I not on “the list?”

Many will agree that exida's Safety Equipment Reliability Handbook (SERH) and the Safety Automation Equipment List (SAEL) are very useful tools for choosing products to use in safety instrumented systems. The SAEL shows a product’s IEC 61508 and cyber security compliance information. In addition, the SERH has a full set of failure rate and failure mode data for each product. However not every product on the market is included. So some may wonder why certain equipment, with published reliability data and/or IEC 61508 certification, is not listed in the SERH and/or SAEL. The reason is simple: the analysis and/or assessment done on the product does not meet exida’s reasonability checks for listing the specific…

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