High Quality Content by WIKIPEDIA articles! The Viable Systems Approach (VSA) is a system theory in which the observed entities and their environment are interpreted through a systemic viewpoint, starting with the analysis of fundamental elements and finally considering more complex related systems (von Bertalanffy, 1968). The assumption is that each entity/system is related to other systems, placed at higher level of observation, called supra-systems, whose traits can be detected in their own subsystems (principle of system hierarchy). As such, the fundamental unit of analysis is a system made up of many parts or structures (Parsons, 1971). In this sense, every entity (a firm, or simply an individual, a consumer, or a community) as a system can be considered a micro-environment, made up of a group of interlinked sub-components which aim towards a common goal (this is the condition, for the aggregate, to be qualified as a system). The Viable System Model was first proposed by Beer and then developed by Christopher. In general terms, a viable system is finalized toward its vitality throughout viable behavior based upon consonant and resonant relationships (Barile, 2000; Golinelli, 2000, 2005, 2010; Barile, 2008, 2009).