"Technical systems consist of designed links/relations that do not normally change. But socio-technical systems...." #readingToday
[S]ince we do not know precisely how the parts of a socio-technical system relate to one another, and in particular do not know precisely how activities relate to one another, then we should not be surprised if two seemingly unrelated persons or activities in fact may be coupled to each other. Technical systems consist of components with designed links and relations that do not normally change. But socio-technical systems are not designed and may hide uncharted and unknown dependencies or couplings. The small world phenomenon demonstrates the importance of this, namely that things (actions) that seemingly have no relation to each other still may affect each other. Such effects are of course made stronger if couplings can interact with and reinforce each other. The critical issue in risk assessment it not just that the number of combinations is too large to handle. The critical issue is that we need to be able to account for the couplings that emerge in socio-technical systems in order to be able to understand the risks of the future.
The ETTO Principle, Erik Hollnagel