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Functional Safety Play Book
258 members • Free
2 contributions to Functional Safety Play Book
24d •
Quick question for the community
What's the most useful thing you've found here so far, and is there anything you wish was in there that isn't yet? Asking because I want to make sure what I build next actually reflects what engineers here need. Drop a comment below. ☺️
2 likes • 23d
I found it very beneficial for me as newbie in functional safety, just passed TUV rheinland functional safety last year, but still have many questions in mind especially after practicing in the real project. I'm planning to take exida CFSE someday so this would boost my understanding in functional safety topics. Personally, i wish to have the deep discussion about the basic things in functional safety just like my previous question regarding mission time that the definition seems unclear, especially all the parameters in SRS from all the experts here.
Jan 8 •
Mission Time
Hi all, thanks for accepting. First of all, I am new in functional safety and sorry for my bad english😊. Actually I have some doubt about one of variable in PFDavg calculation namely mission time, couple of question to all: 1. What will happen in the end of mission time?should end user decommissioned the plant?or just replace everything and the mission time will get restarted? 2. If it depend on end user, than based on what consideration usually for them to determine the correct mission time?and what is the reason behind that? 3. Since by the time PFDavg will get derated, and SIL claimed may decreased over the time, shouldn't end user decide to set the mission time before the SIL/RRF drops beyond the rating it should be? Hope you guys can share your knowledge. Thanks,
0 likes • Mar 25
@Harvey Dearden hi harvey, thanks for the comment, i think realistically PFDavg will never return to zero as Proof test coverage will never have 100% coverage. PFDavg will then accumulated over the mission time. Just wondering what to do in the end of mission time, should we refurbish everything or replace with new equipment? And can it returned the PFDavg value to zero. Or basically the plant will be decommissioned in the end of mission time.
1 like • 29d
@Tomasz Barnert exactly, i am struggle to elaborate the definition of it to customer, ideally they should know better than me as system integrator, but not every end user knows this terminology, whereas we need to know that information as well from them.
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Active 17d ago
Joined Jan 5, 2026