Archives For Safety

The practice of safety engineering in various high consequence industries.

MH370 underwater search area map (Image source- Australian Govt)

After millions of dollars and years of effort the ATSB has suspended it’s search for the wreck of MH370. There’s some bureaucratic weasel words, but we are done people. Of course had the ATSB applied Bayesian search techniques, as the USN did in the successful search for it’s missing  USS Scorpion, we might actually know where it is.

M1 Risk_Spectrum_redux

A short article on (you guessed it) risk, uncertainty and unpleasant surprises for the 25th Anniversary issue of the UK SCS Club’s Newsletter, in which I introduce a unified theory of risk management that brings together aleatory, epistemic and ontological risk management and formalises the Rumsfeld four quadrant risk model which I’ve used for a while as a teaching aid.

My thanks once again to Felix Redmill for the opportunity to contribute.  :)

Joshua Brown screen grab

Keep your eyes on the road, and your hands upon the wheel…

The first fatality involving the use of Tesla’s autopilot* occurred last May. The Guardian reported that the autopilot sensors on the Model S failed to distinguish a white tractor-trailer crossing the highway against a bright sky and promptly tried to drive under the trailer, with decapitating results. What’s emerged is that the driver had a history of driving at speed and also of using the automation beyond the maker’s intent, e.g. operating the vehicle hands off rather than hands on, as the screen grab above indicates. Indeed recent reports indicate that immediately prior to the accident he was travelling fast (maybe too fast) whilst watching a Harry Potter DVD. There also appears to be a community of like minded spirits out there who are intent on seeing how far they can push the automation… sigh.  Continue Reading…

System Safety Fundamentals Concept Cloud

Have just updated the safety case module for the system safety course I teach at UNSW. Have revised it to include John Rushby’s approach to determining the soundness and strength of a safety argument (I like his simplification and separation of concerns strategy). Enjoy!

Morely.png

Why writing a safety case might (actually) be a good idea

Frequent readers of my blog would probably realise that I’m a little sceptical of safety cases, as Scrooge remarked to Morely’s ghost, “There’s more of gravy than of grave about you, whatever you are!” So to for safety cases, oft more gravy than gravitas about them in my opinion, regardless of what their proponents might think.

Continue Reading…

Here’s a short presentation  I gave on the ramifications of the Australian model WHS Act (2011) for engineers when they engage in, or oversee design. The act is a complex beast, and the ramifications of it have not yet fully sunk into the engineering community.

One particularly contentious area is the application of the act to plant and materials that are imported. While the guidance material for the act gives the example of a supplier performing additional testing of the goods to demonstrate it meets Australian Standards, the reality is well, a little different.

Monkey-typing

Safety cases and that room full of monkeys

Back in 1943, the French mathematician Émile Borel published a book titled Les probabilités et la vie, in which he stated what has come to be called Borel’s law which can be paraphrased as, “Events with a sufficiently small probability never occur.” Continue Reading…