Archives For Systems of Systems
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.
While once again the media has whipped itself into a frenzy of anticipation over the objects sighted in the southern Indian ocean we should all be realistic about the likelihood of finding wreckage from MH370.
The MIL-STD-882 lexicon of hazard analyses includes the System Hazard Analysis (analysis) which according to the standard is intended to:
“…examines the interfaces between subsystems. In so doing, it must integrate the outputs of the SSHA. It should identify safety problem areas of the total system design including safety critical human errors, and assess total system risk. Emphasis is placed on examining the interactions of the subsystems.”
This sounds reasonable in theory and I’ve certainly seen a number toy examples touted in various text books on what it should look like. But, to be honest, I’ve never really been convinced by such examples, hence this post.
The Mississippi River’s Old River Control Structure, a National Single Point of Failure?
Given the recent events in Fukushima and our subsequent western cultural obsession with the radiological consequences, perhaps it’s appropriate to reflect on other non-nuclear vulnerabilities. A case in point is the Old River Control Structure erected by those busy chaps the US Army Corp of Engineers to control the path of the Mississippi to the sea. Well as it turns out trapping the Mississippi wasn’t really such a good idea…
Just discovered a paper I co-authored for the 2006 AIAA Reno Conference on the Risk & Safety Aspects of Systems of Systems. A little disjointed but does cover some interesting problem areas for systems of systems.