Modelling infrastructures as socio-technical systems

The conceptualization of the notion of a system in systems engineering, as exemplified in, for instance, the engineering standard IEEE Std 1220-1998, is problematic when applied to the design of socio-technical systems. This is argued using Intelligent Transportation Systems as an example. A preliminary conceptualization of socio-technical systems is introduced which includes technical and social elements and actors, as well as four kinds of relations. Current systems engineering practice incorporates technical elements and actors in the system but sees social elements exclusively as contextual. When designing socio-technical systems, however, social elements and the corresponding relations must also be considered as belonging to the system.