Second part of the SBS documentary on line now. Looking at the IoT this episode.
Cyberwar documentary now running on SBS with a good breakdown of the Stuxnet malware courtesy of the boys at Symantec. Thank you NSA, once again, for the bounty of Stuxnet… Yes, indeed thank you.
So, we have a Trump Presidency in the wings. What a total shock it was to all those pollsters, commentators and apparatchiks who got it so wrong, and is also a textbook example of a Black Swan event. Continue Reading…
An Outside Context Problem was the sort of thing most civilisations encountered just once, and which they tended to encounter rather in the same way a sentence encountered a full stop.
More infernal statistics
Well, here we are again. Given recent developments in the infernal region it seems like a good time for another post. Have you ever, dear reader, been faced with the problem of how to achieve an unachievable safety target? Well worry no longer! Herewith is Screwtape’s patented man based mitigation medicine.
The first thing we do is introduce the concept of ‘mitigation’, ah what a beautiful word that is. You see it’s saying that it’s OK that your system doesn’t meet its safety target, because you can claim credit for the action of an external mitigator in the environment. Probability wise if the probability of an accident is P_a then P_a equals the product of your systems failure probability P_s and. the probability that some external mitigation also fails P_m or P_a = P_s X P_m.
So let’s use operator intervention as our mitigator, lovely and vague. But how to come up with a low enough P_m? Easy, we just look at the accident rate that has occurred for this or a like system and assume that these were due to operator mitigation being unsuccessful. Voila, we get our really small numbers.
Now, an alert reader might point out that this is totally bogus and that P_m is actually the likelihood of operator failure when the system fails. Operators failing, as those pestilential authors of the WASH1400 study have pointed out, is actually quite likely. But I say, if your customer is so observant and on the ball then clearly you are not doing your job right. Try harder or I may eat your soul, yum yum.
Never confuse volume with authority.