Viable System Model (VSM)
What is Stafford Beer's Viable System Model (VSM)?
The viable system model is a model of the organizational structure of any autonomous system capable of producing itself. A viable system is any system organized in such a way as to meet the demands of surviving in the changing environment. One of the prime features of systems that survive is that they are adaptable. 
The Viable System Model (VSM) is a model developed by Stafford Beer to help organizations adapt to changing environments. It describes how organizations can harness the principles of complexity and variety management to do this, and specifies the necessary and sufficient conditions for any organization to remain viable. The VSM comprises five key components: system boundaries, technology drivers, system performance, system effects, and system sustainability. The model is used to assess the impact of technology on organizations and devise strategies for managing it.