Current modeling approaches in the field of learning and work resemble the notion of workflows and hence fall short in describing the situated and socially mediated nature of practices. Against this background the paper describes an alternative modeling approach as well as its theoretical foundation and practical implications. As this paper rethinks the epistemological foundation of modeling socio-technical systems, the approach goes beyond specifying specific concepts and relations and addresses the meta-level of modeling. The cultural historical activity theory as well as the theory of social systems work as the theoretical foundation.