Based on a system-theoretical approach, aspects of real world systems have been introduced. In this context, the relations between a system's architecture, i.e. its components, their functions and relations, formally represented by domain-specific ontologies considering all domains relevant in the system's use case on the one hand and the system's behaviour ruled by the applied policies on the other hand have been described. A refinement of policies ruling a clinical setting has been exemplified. It could be shown that ubiquitous health systems must be designed and managed following a thoroughly systems-oriented, architecture-centric, ontology-based and policy-driven approach. The feasibility of the approach has been practically demonstrated.