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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Entries tagged with: Failure Rate
- 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…
- by Dr. William Goble, CFSE
- Tuesday, July 07, 2020
- Functional Safety
OLD component data = Bad FMEDAs
When we first invented the FMEDA technique in the late 1980s the biggest problem was the component failure rate and failure mode data. Still is. I picked up a well-known standard for component failure rates and saw a date of 2010. The technology world has gone through an order of…
- by Dr. William Goble, CFSE
- Thursday, May 17, 2012
- Functional Safety
The Battle of the Failure Rates
Site Specific vs. Product Specific
During a field failure analysis study, it was discovered that the calculated failure rate of a specific device varied by more than 4X depending on installation site. Particularly, it was one specific site with a high failure rate. While any reliability engineer…