Back to Basics: Failure Rates – λD

by | Apr 2, 2020 | Blogs

[:en][vc_row][vc_column][vc_column_text] The Greek symbol  λD represents dangerous failure rates in functional safety, usually expressed in the unit of measurement of FITs, and can be determined through FMEDAs. (FITs (λ) are failures per billion hours, expressed by...

Why Run-to-Fail Is Not A Good Maintenance Strategy For SIS

by | Jun 22, 2017 | Blogs

[vc_row][vc_column][vc_column_text]One of the fundamentals of the Probability of Failure on Demand (PFDavg)calculations in SIL verification analysis, is the concept of a constant failure-rate during useful life of the equipment.  Probabilistic calculations assume that...

Random Versus Systematic Faults: What’s The Difference?

by | Oct 19, 2017 | Blogs

[:en][vc_row][vc_column][vc_column_text]I saw and responded to a LinkedIn discussion on this very issue, where someone had asked “if I have a misaligned limit switch that fails dangerously, then is it random or systematic?”. This is an intriguing question...