Archives For Complexity

Complexity, what is, how do we deal with it, and how does it contribute to risk.

Here’s a companion tutorial to the one on integrity level partitioning. This addresses more general software hazards and how to deal with them. Again you can find a more permanent link on my publications page. Enjoy :)

SR-71 flight instruments (Image source: triddle)

How a invention that flew on the SR-71 could help commercial aviation today 

In a previous post on unusual attitude I talked about the use of pitch ladders as a means of providing greater attensity to aircraft attitude as well as a better indication of what the aircraft is dong, having entered into it. There are of course still disadvantages with this because such data in a commercial aircraft is usually presented ‘eyes down’, and in high stress, high workload situations it can be difficult to maintain an instrument scan pattern. There is however an alternative, and one that has a number of allied advantages. Continue Reading…

Unreliable airspeed events pose a significant challenge (and safety risk) because such situations throw onto aircrew the most difficult (and error prone) of human cognitive tasks, that of ‘understanding’ a novel situation. This results in a double whammy for unreliable airspeed incidents. That is the likelihood of an error in ‘understanding’ is far greater than any other error type, and having made that sort of error it’s highly likely that it’s going to be a fatal one. Continue Reading…

AirAsia QZ8501 CVR (Image source - AP Photo-Achmad Ibrahim)

Stall warning and Alternate law

According to an investigator from Indonesia’s National Transportation Safety Committee (NTSC) several alarms, including the stall warning, could be heard going off on the Cockpit Voice Recorder’s tape.

Now why is that so significant?

Continue Reading…

Boeing 787-8 N787BA cockpit (Image source: Alex Beltyukov CC BY-SA 3.0)

The Dreamliner and the Network

Big complicated technologies are rarely (perhaps never) developed by one organisation. Instead they’re a patchwork quilt of individual systems which are developed by domain experts, with the whole being stitched together by a single authority/agency. This practice is nothing new, it’s been around since the earliest days of the cybernetic era, it’s a classic tool that organisations and engineers use to deal with industrial scale design tasks (1). But what is different is that we no longer design systems, and systems of systems, as loose federations of entities. We now think of and design our systems as networks, and thus our system of systems have become a ‘network of networks’ that exhibit much greater degrees of interdependence.

Continue Reading…

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In case anyone missed it the Ebola outbreak in Africa is now into the ‘explosive’ phase of the classic logistics growth curve, see this article from New Scientist for more details.

Here in the west we get all the rhetoric about Islamic State as an existential threat but little to nothing about the big E, even though this epidemic will undoubtedly kill more people than that bunch of crazies ever will. Ebola doesn’t hate us for who we are, but it’ll damn well kill a lot of people regardless.

Another worrying thought is that the more cases, the more generations of the disease clock over and the more chance there is for a much worse variant to emerge that’s got global legs. We’ve been gruesomely lucky to date that Ebola is so nasty, because it tends too burn out before going to far, but that can change ver quickly. This is a small world, and what happens inside a village in West Africa actually matters to people in London, Paris, Sydney or Moscow. Were I PM that’s where I’d be sending our defence force, not back into the cauldron of the Middle East…

London Science Museums Replica Difference Engine (Image source: wikipedia)

An amusing illustration of the power of metadata, Finding Paul Revere, by Kieran Healy. Clearly what the British colonial administration in America lacked was a firm grasp of the mathematical principles embodied in social network theory, Ada Lovelace on consultancy and a server park filled with Mr Babbage’s difference engines. If they had, then the American revolution might well have had a very different outcome. :)