exida explains Blog

Entries tagged with: William Goble

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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exida Failure Rates are Higher Than TÜV Italia. Who Is Right?
  • by Dr. William Goble, CFSE
  • Tuesday, March 05, 2019
  • Certification

exida Failure Rates are Higher Than TÜV Italia. Who Is Right?

An owner-operator engineer compared the failure rates for two similar products from an exida certificate with those from a TÜV Italia certificate.  exida numbers were an order of magnitude higher.  Who is right?  

There are some relevant fundamental facts in the field of Reliability Engineering:

  1. Failure rate prediction methods depend…

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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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Using SILSafeData to Check Your Failure Data Source
  • by Dr. William Goble, CFSE
  • Monday, October 29, 2018
  • Certification

Using SILSafeData to Check Your Failure Data Source

www.SILSafeData.com is a complimentary resource that contains the upper and lower bounds failure rates for many categories of automation equipment, as well as the methodology used by exida to derive the numbers.  

Many of you have asked how to…

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Who gives exida the authority to publish SILSafeData?
  • by Dr. William Goble, CFSE
  • Thursday, January 24, 2019
  • Certification

Who gives exida the authority to publish SILSafeData?

SILSafe Data

SILSafeData contains upper and lower bound ranges of dangerous undetected failure rates for many automation devices. It was created by exida using statistical analysis of FMEDA failure rate predictions. The component database used in the FMEDAx tool is based on…

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