Systems theory, or general systems theory, deals with the study of whole systems -- their properties, principles, and common attributes. Holistic inquiry and system dynamics are part of systems theory.
Systems theory brought together theoretical concepts and principles from ontology, philosophy of science, and several other fields of science, including organizational theory, management, and economics, among others. It focuses on organization and interdependence of relationships - in the case of the business model this is expressed as the organization and interrelationships of the business model elements, the elements making up the business organization.
