I'm surprised to see that this question How to roughly know if a electronic scheme will fail soon and protect from it? has been put on hold as primarily opinion-based.

It could (maybe) have been put on hold as too broad, because the OP could've narrowed more the question. But, in any case, it's clear to me that the question can be objectively answered within the framework of RAMS engineering, a very specific expertise field.

The OP was asking (maybe without knowing the exact technical terms) two things:

  1. Is there any reliability data (MTTF, failure rate...) available for Raspberry Pi and/or similar SBCs?

  2. How can I calculate the MTTF (mean time to failure) and then the MTTM (mean time to maintenance) so I can preemptively replace the boards before a failure?

This is not the realm of "almost entirely based on opinions, rather than facts, references, or specific expertise". It's 100% reliability engineering.

Would it be worth if a moderator corrected this situation? Or, alternatively, what changes needs the question in order to be reopened?

Additional note:

I was really curious about what could other people with RAMS background answer to the OP's question. I'm here to volunteer, but also to learn. That could have been a good question for someone with firmware/software RAMS background to step in. My answer was focused just in the hardware aspects of RAMS.


4 Answers 4


In addition to the actual reasons for this question being closed, as given by the other answers, it's also worth noting that the voting system is not without its own flaws. Sometimes questions are not closed fast enough, and sometimes they are closed too quickly. In this case, you identified a question that was treated unfairly in one way or the other, notified the "proper authorities", the question was re-opened, and arguably the system worked.

The problem as I see it is that when I review questions that are nominated for closure, I'm already biased: "This is a bad question, someone has nominated it, or someone else have voted". For a reviewer (at least for me!), this makes it easier to lean toward adding your close vote instead of using the equally important Leave Open button:

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I probably use it less often than I should. It is something I have been thinking of more, the longer I've had the option to vote.

  • \$\begingroup\$ I agree with your reflections here. The system has some kind of "bandwagon effect" built in. Sometimes I feel inclined to downvote or VTC just because someone else did too. I have to actively fight that bias in order to be as fair as possible (and I might not succeed always... I'm human after all). \$\endgroup\$ Apr 21, 2017 at 21:47

Sometimes the close reason does not match up with why a question is really closed, and this is one such case, I think.

Your answer about RAMS approaches was very comprehensive and interesting -- which is why I didn't vote to close. That said, let's divorce the answer and look at the question, which is the basis for the close votes.

There is nothing in that question which would lead one to believe that the level of solution you offer, which involves a large investment and commitment to quality systems, is the path that the asker is looking for. In fact, the user is asking "how do I know when a sensor is about to break" without even telling us what the sensors in question are. As such, the question is simply unanswerable (though somebody should have pointed out that for dependability, one should probably avoid a linux system running entirely off an SD card). Further, the failure modes the user will likely encounter will have very little to do with the "durability of the boards" so much as design decisions to use the boards out of specified conditions. So A) Not enough info is provided, and B) The asker is probably asking the wrong question.

I'm not inclined to personally close such questions, but that's the community-moderated model SE goes by. Not every close will be stellar, or even right. I suppose some questions are worth arguing about, but this doesn't seem like its all that answerable to me.

I like your answer, and I suggest that you post a GOOD question to match it, and then provide the answer, in proper context, where people looking for such an answer will be likely to find it in a search. Answering your own question is not discouraged in the SE model, and this might be a great use of the technique, to get your great RAMS approach into the archive in a better context.

  • \$\begingroup\$ Thank you for your answer, it's very reasonable. I'll seriously consider your suggestion about posting a matching question. \$\endgroup\$ Apr 19, 2017 at 16:38
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    \$\begingroup\$ @EnricBlanco -- when you post the question, just be quick about following with the answer, so I'm not tempted to cut and paste your answer! ;) \$\endgroup\$ Apr 19, 2017 at 16:57
  • \$\begingroup\$ Hahaha! That's a good suggestion, too. :D \$\endgroup\$ Apr 19, 2017 at 17:44
  • \$\begingroup\$ The OP needs a lot more work on this question and the question needs to be answerable. People can still vote on the question with the answer you provided, and it looks like you gave a good answer. Why would you want the question to remain open for more answers? \$\endgroup\$
    – Voltage Spike Mod
    Apr 19, 2017 at 20:51
  • \$\begingroup\$ @laptop2d Thank you for leaving your opinion/vote about my answer. \$\endgroup\$ Apr 19, 2017 at 21:13

Lets look at the question:

So, I wonder, if there is information about how durable the boards are and if they are suitable for 24/7 work during weeks/months?

How do I make sure that system has some more or less definite margin of safety and know the moment when I should replace it with a new one?

The answer to this question would be "No, these boards are not designed for safety-critical applications so no such data is available for them". Or a link to the data. Anything else is called speculation in my book.

You wrote a nice piece of text, but I sincerely doubt it was of any practical use to the OP and the future readers. Imagine a guy googling for "How long my board will last" and finding your answer. Do you expect them to set up an accelerated aging stand and run tests on a bunch of boards to find out? Again, I'm not questioning the quality of your answer here, just pointing out that the actual question wasn't worth answering (none of the answers do it), that's why it got closed.

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    \$\begingroup\$ A system doesn't need to be designed for safety-critical applications to have a MTBF, in fact everything has an implicit MTBF. A lot of COTS (non-hirel) AC-DC converters disclose MTBF figures in their datasheets calculated according to MIL-HDBK-217F. \$\endgroup\$ Apr 21, 2017 at 14:49

The forum seems to prefer simplistic questions that can be easily answered with a yes /no /add another resistor type statements. It's not really suitable for instances where much analysis is required. Hence the notion of "opinions". You must know this with your reputation score. Clearly all answers on this site are opinions, it just appears that some peoples' opinions are more valid than others. I recently asked about this very thing, but the question was unpopular and therefore deleted off the main list. If you review this Meta you'll see all SE criticism is unpopular.

I can only tell you the advice they gave me before deleting my question. "Grow up and get over it...It's what happens on this site...you really need to learn to recognise questions that are wrong...Why do you care as it's only an answer?"

So get over it and move on is the take away from Meta. (Shame really. That would have been a good answer.)

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    \$\begingroup\$ I sincerely understand your frustration. However, I don't want to go down the rant route myself in this meta question. The OP's question (and thus my answer) probably won't get deleted. I'm just concerned about that poor guy OP not getting any further help (just my answer). Also, I was curious about what could other people with RAMS background answer to the OP's question. I'm here to volunteer, but also to learn. That could have been a good question for someone with firmware/software RAMS background to step in. My answer was focused just in the hardware aspects of RAMS. \$\endgroup\$ Apr 19, 2017 at 14:53
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    \$\begingroup\$ How was your question "deleted off the main list"? You linked to it, and the link works - so its still there. Seems a number of people disagree with your point of view and some went to lengths to explain why. \$\endgroup\$
    – brhans
    Apr 19, 2017 at 19:10

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