Functional Safety standards distinguish between systematic and random failures. The definitions attempt to clarify how to categorize real failures. The standards also explain that random failures are included in probabilistic failure analysis and systematic failures require changes in operating procedures.
However, it is clear that all real failures may prevent a safety system from performing its safety protection. Therefore any field failure collection system must count all real failures until it is shown by new failure records that a change in a procedure is effective in eliminating a type of failure.
This webinar shows the results of a recent survey where respondents classified real failures. It will be shown that many failures classified as systematic would result in an unrealistically low failure rate and possibly dangerous designs.
Loren Stewart graduated from Virginia Tech with a BSME. She has over 10 years of professional experience. She currently works for exida consulting as a safety engineer, focusing on the mechanical aspects of their customers. Along with assessing the safety of products and creating FMEDAs and reports, she researches stiction and is creating a database for the 2H initiative according to IEC 61508.