Before revision: 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 ( Ludwig von Bertalanffy, 1968).
After revision: The viable systemss 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).