<P> Systems theory in political science is a highly abstract, partly holistic view of politics, influenced by cybernetics . The adaptation of system theory to political science was first conceived by David Easton in 1953 . </P> <P> In simple terms, Easton's behavioral approach to politics, proposed that a political system could be seen as a delimited (i.e. all political systems have precise boundaries) and fluid (changing) system of steps in decision making . Greatly simplifying his model: </P>

Who has established the concept of input output model in political system