Prior Use and PFDavg calculations · Functional Safety Play Book

Jan 29 (edited) • Functional Safety Question ❓

Prior Use and PFDavg calculations

I saw this question somewhere and I thought I would pick your opinion on it.

Since prior-use justification addresses systematic capability and hardware constraints only, and SIL verification still requires meeting the three barriers per IEC 61511, how is PFDavg calculated when using prior-use devices that lack defined failure rate data?

2 comments