To be an AoG, the test has to be 'No-one would have thought of that.'
I don't know much about how the 'functional safety' experts have
re-normalized their infinities, but I believe that, having acknowledged
that 'anything not violating the laws of physics can happen',
nevertheless have adopted values of 'infinitesimal probability'. This
allows for a black swan that can play the piano.
Best wishes
With seasonal felicitations
John Woodgate OOO-Own Opinions Only
Rayleigh, Essex UK www.woodjohn.uk
On 2019-12-30 20:39, Douglas Nix wrote:
Two thoughts on this:
1) it sounds from the the description of the event that this might
also be called a “black swan” event. As we all know, black swans are
real, however rare they may be. This is simply another way to say “We
never thought of that”, and
2) I had a Trek mountain bike that had a reminder in the manual that
“you mountain bike is not a submarine”, as a way to remind owners that
riding your bike with the hubs an drive train submerged was a good way
to kill the bearings if one didn’t immediately service them after
submersion.
IMO, although the process functional safety folks will often argue
that black swans need not be considered, it’s my opinion that we need
to understand them and mitigate them if the analysis shows that
perhaps they are more gray than black. “Acts of God” have no place in
product safety as far as I’m concerned. Understand the hazards and the
best understanding of the probabilities that can be developed, and
mitigate to the state of the art.
Doug Nix
[email protected] <mailto:[email protected]>
Life should NOT be a journey to the grave with the intention of
arriving safely in a well preserved body, but rather to skid in
broadside, thoroughly used up, totally worn out, and loudly
proclaiming -- WOW -- What a RIDE!!
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