Archives For Complexity

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

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.

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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. :)

Toyota ECM (Image source: Barr testimony presentation)

Comparing and contrasting

In 2010 NASA was called in by the National Highway Transport Safety Administration to help in figuring out the reason for reported unintended Toyota Camry accelerations. They subsequently published a report including a dedicated software annex. What’s interesting to me is the different outcome and conclusions of the two reports regarding software.  Continue Reading…

Tweedle Dum and Dee (Image source: Wikipedia Commons)

Revisiting the Knight, Leveson experiments

In the through the looking glass world of high integrity systems, the use of N-version programming is often touted as a means to achieve extremely lower failure rates without extensive V&V, due to the postulated independence of failure in independently developed software. Unfortunately this is hockum, as Knight and Leveson amply demonstrated with their N version experiments, but there may actually be advantages to N versioning, although not quite what the proponents of it originally expected.

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System Safety Fundamentals Concept Cloud

There’s a very interesting site,  run by a couple of Australian lads, called Text is Beautiful that provides some free tools that allow you to visually represent the relationships within a text. No this isn’t the same as Wordle, these guys have gone beyond that to develop what they call a Concept cloud, colours in the Concept Cloud are indicative of distinct themes and themes themselves represent rough groupings of related concepts. What’s a concept? Well a concept is made up of several words, with each concept having it’s own unique thesaurus that is statistically derived from the text.

So without further ado I took the Fundamentals of System Safety course that I teach and dropped it in the hopper, the results as you might guess are above. Very neat to look at and it also gives an interesting insight into how the concepts that the course teaches interrelate. Enjoy. :)

Well I can’t believe I’m saying this but those happy clappers of the software development world, the proponents of Agile, Scrum and the like might (grits teeth), actually, have a point. At least when it comes to the development of novel software systems in circumstances of uncertainty, and possibly even for high assurance systems.

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