[SystemSafety] A Series of SW-related Sociotechnical System Failures

[Peter Bernard Ladkin]

There's a new paper on the RVS publications page at
http://www.rvs.uni-bielefeld.de/publications/Papers/LadkinSocioTechDB20150113.pdf

It's not about a safety-critical system. It's about my experience with a WWW-based ticketing system.
However, the observations are very similar. People aren't thinking about - or specifying - the
system function, and they are in particular not checking that the implemented system is (in this
case, isn't) a refinement of the system function as it should be. Operators are apparently adapting
as Rasmussen says they do - Migration to the Boundary - but it's not clear to me that they should be.

What managed to happen in this case is that a system with virtually 100% reliability over years went
down to 39% reliability in the last year and a half. So much for computers helping!

Best practice in design and evaluation is the same, it seems to me, as in critical systems. That
should be good news, on the basis that we need to keep on banging the same old drum. But it could be
bad news if we are doing so in a vacuum......

PBL

Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany
Je suis Charlie
Tel+msg +49 (0)521 880 7319  www.rvs.uni-bielefeld.de