Provided as part of the QR show bag for the CORE 2012 conference. The irony of a detachable cab being completely unintentional…
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But, we tested it? Didn’t we?
Earlier reports of the Boeing 787 lithium battery initial development indicated that Boeing engineers had conducted tests to confirm that a single cell failure would not lead to a cascading thermal runaway amongst the remaining batteries. According to these reports their tests were successful, so what went wrong?
Over on the RVS Bielefield site Peter Ladkin has just put up a white paper entitled 61508 Weaknesses and Anomalies which looks at the problems with the current version of the IEC 61508 functional safety standard, part 6 of which sits on my desk even as we speak. Comments are welcome.
Dr Nancy Leveson will be teaching a week-long class on system safety this year at the Talaris Conference Center in Seattle from July 15-19.
Her focus will be on the new techniques and approaches described in her latest book Engineering a Safer World. Should be excellent.
See the class announcement for further details.
The WordPress.com stats prepared a 2012 annual report for this blog.
Here’s an excerpt:
4,329 films were submitted to the 2012 Cannes Film Festival. This blog had 29,000 views in 2012. If each view were a film, this blog would power 7 Film Festivals
A Working Definition and a Key Question…
One of the truisms of systems safety theory is that safety is an emergent attribute of the design. But looking at this in reverse it also implies that system accidents are emergent, if unintended, attributes of a system. So when we talk about system accidents and hazards we’re really (if we accept the base definition) talking about an emergent attribute of a system.
But what are emergent attributes? Now that is a very interesting philosophical question, and answering it might help clarify what exactly is a system accident…
Just put the final conference ready draft of my Writing Specs for Fun and Profit up, enjoy!
As readers may have noted, I’ve changed the name of my blog to Critical Uncertainties which I think better represents what it’s all about, well at least that’s my intent. 🙂
I’m still debating whether to go the whole hog and register a domain name, it has it’s advantages and disadvantages. But if I do don’t worry, my host WordPress.com will make sure that you don’t get lost on the way here.
P.S I did think of a few alternate names. Some better than others…
Neil Armstrong died yesterday at the age of 82, and rather than celebrating his achievements as an astronaut, marvelous though they are, I’d like to pay tribute here to his work as an engineer and test pilot.
Before Apollo Neil Armstrong was a test pilot for NACA flying the X15 rocket plane, and during his test piloting he came up with what they ended up calling the Armstrong spiral. The manoeuvre was a descending glide spiral that tightened the turn radius as the glide speed reduced. Armstrong’s manouevre was so widely regarded that it was later adopted by the Space Shuttle program.
Fast forward to 4 November 2010 and Richard De Crespigny the Captain of QF 32 after experiencing a catastrophic engine failure and faced with the potential for a glide back to Changi remembers and uses the Armstrong approach in his plan for an engine out approach.
So misquote Shakespeare, sometimes the good that men do is not interred with them.
How driver training problems for the M113 Armoured Personnel Carrier provide and insight into the ecology of interface design.Continue Reading...
How do ya do and shake hands, shake hands, shake hands. How do ya do and shake hands and state your name and business…
Lewis Carrol, Through the Looking Glass
You would have thought after the Leveson and Knight experiments that the theory that independently written software would only contain independent faults was dead and buried, another beautiful theory shot down by hard cold fact. But unfortunately like many great errors the theory of n-versioning keeps on keeping on (1).