  Causal Models are increasingly suggested as a means to reason about the
behavior of cyber-physical systems in socio-technical contexts. They allow us
to analyze courses of events and reason about possible alternatives. Until now,
however, such reasoning is confined to the technical domain and limited to
single systems or at most groups of systems. The humans that are an integral
part of any such socio-technical system are usually ignored or dealt with by
"expert judgment". We show how a technical causal model can be extended with
models of human behavior to cover the complexity and interplay between humans
and technical systems. This integrated socio-technical causal model can then be
used to reason not only about actions and decisions taken by the machine, but
also about those taken by humans interacting with the system. In this paper we
demonstrate the feasibility of merging causal models about machines with causal
models about humans and illustrate the usefulness of this approach with a
highly automated vehicle example.
