The main purpose of this paper is to highlight the new opportunities that the Viable Systems Approach (VSA) can provide for observing complex service  systems and explaining social phenomena through general schemes of interpretation. At the same time, it explores methodological links with the Service Science (SS)  pproach in order to propose (VSA)’s contribution to moulding a unified vision of complex objects of analysis, and to evidence the many converging elements that  emerge from the two perspectives as well as the benefits that derive from different interpretation schemes. In particular, in our paper we analyze healthcare service  complexity in a relational perspective, using a VSA-SS conceptual framework to interpret the emergent systems instability in the Italian Health Service. The  application of principles and concepts proper to the (VSA) and the SS approaches to articulated service structures, such as healthcare, identifies critical features  and interesting new “therapeutic” prospects for healthcare service systems in order to guarantee their viability. The paper proposes an innovative methodological  basis for evaluating the level of appropriateness of the healthcare service and, at the same time, evidences the need for achieving a balanced triple target of efficiency, effectiveness and sustainability (EES) in healthcare service systems governance. As a result, a new area of cross fertilization for collaborative research emerges.