While correcting a CFSP exam, I read a question which went something like this:
If you purchase all IEC 61508 certified equipment for a low demand safety instrumented function, then to meet the requirements of IEC 61511:
A. No other design verification is needed
B.…
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…
In today’s modern society there is an increasing demand for “safer” products/systems, which have to meet increasingly demanding standards. The management of “risk” is a major factor in ensuring that a product/system can meet its design objectives, as well as satisfying the required standards and, even more importantly, meeting…
The solenoid valve manufacturer provides an FMEDA report that lists “useful life = 12 years.” Useful life is a reliability engineering term that indicates a point in time when the failure rate of a device will begin increasing rather rapidly. Why do we care about this time interval? That…
There have been passionate debates in email and meetings about “Proven In Use” versus IEC 61508 certification. Most debates characterize 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…
exida has been gathering field failure data for over a decade. At this point we have a total of over 60 billion unit operating hours of field data for process industry devices. This data has been used to create a 2H database for components. exida is using this component…
The publication of the international functional safety standards IEC 61508 (1999), IEC 61511 / ISA-84 (2004) and IEC 62061 (2005) were significant milestones in the effort to increase equipment and process safety. 1,2,3 Unfortunately, the release of safety standards does not by itself make the world a safer place.…