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Just for information, we did some code verification on an industrial real-time product (with a real-time operating system) and the majority of faults that mattered were concurrency bugs.<br>
<br>
And the trigger for lot of these were a combination of internal state conditions (and, in some cases, external hardware failure). <br>
<br>
So not deterministic in the usual sense of having repeatable failure for a given test - because there are additional variables that cannot be controlled.<br>
<br>
Peter Bishop<br>
Adelard</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> systemsafety <systemsafety-bounces@lists.techfak.uni-bielefeld.de> on behalf of Derek M Jones <derek@knosof.co.uk><br>
<b>Sent:</b> 13 August 2024 15:54<br>
<b>To:</b> systemsafety@lists.techfak.uni-bielefeld.de <systemsafety@lists.techfak.uni-bielefeld.de><br>
<b>Subject:</b> Re: [SystemSafety] Difference between software reliability and astrology</font>
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<div class="PlainText">Paul,<br>
<br>
> From previous discussions here and elsewhere (and prior consideration of ISO26262) I was under the impression that
<br>
> software is 'generally recognised' to be (ideally) deterministic?<br>
<br>
Yes, ideally deterministic, not actually deterministic,<br>
but still practically deterministic for many tasks.<br>
<br>
Background radiation (e.g., cosmic rays) is likely to flip<br>
1-bit in 4G os memory every 33 hours<br>
<a href="https://shape-of-code.com/2013/12/13/unreliable-cpus-and-memory-the-end-result-of-moores-law/">https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fshape-of-code.com%2F2013%2F12%2F13%2Funreliable-cpus-and-memory-the-end-result-of-moores-law%2F&data=05%7C02%7Cpeter.bishop%40nccgroup.com%7C029edab1baaa486e4b9608dcbba7dca4%7Ca41111be486b45f68bd0ee01a62f368e%7C0%7C0%7C638591576838648330%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=OtO6yZcCod3nsPriAw0b3YBUONpdD05q%2B2MSQW8HyzY%3D&reserved=0</a><br>
<br>
-- <br>
Derek M. Jones Evidence-based software engineering<br>
blog:https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fshape-of-code.com%2F&data=05%7C02%7Cpeter.bishop%40nccgroup.com%7C029edab1baaa486e4b9608dcbba7dca4%7Ca41111be486b45f68bd0ee01a62f368e%7C0%7C0%7C638591576838658335%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=ZhGGkM8YWp8PF1mPEhpfXigYewfTpYvZe%2F98g6Ip4Jw%3D&reserved=0<br>
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