Systems theories

Systems theory is the interdisciplinary study of systems. A system is an entity with interrelated and interdependent parts; it is defined by its boundaries and it is more than the sum of its parts (subsystem). Changing one part of the system affects other parts and the whole system, with predictable patterns of behavior. Positive growth and adaptation of a system depend upon how well the system is adjusted with its environment, and systems often exist to accomplish a common purpose (a work function) that also aids in the maintenance of the system or the operations may result in system failure. The goal of systems theory is systematically discovering a system's dynamics, constraints, conditions and elucidating principles (purpose, measure, methods, tools, etc.) that can be discerned and applied to systems at every level of nesting, and in every field for achieving optimized equifinality.

General systems theory is about broadly applicable concepts and principles, as opposed to concepts and principles applicable to one domain of knowledge. It distinguishes, dynamic or active systems and static or passive systems. Active systems are activity structures or components that interact in behaviours and processes. Passive systems are structures and components that are being processed. E.g. a program is passive when it is a disc file and active when it runs in the RAM memory. The field is related to systems thinking and systems engineering.

The term "general systems theory" originates from Bertalanffy's general systems theory (GST). His ideas were adopted by others including Kenneth E. Boulding, William Ross Ashby and Anatol Rapoport working in mathematics, psychology, biology, game theory and social network analysis.

Sociological systems thinking started earlier, in the 19th century. Stichweh states: "... Since its beginnings the social sciences were an important part of the establishment of systems theory... the two most influential suggestions were the comprehensive sociological versions of systems theory which were proposed by Talcott Parsons since the 1950s and by Niklas Luhmann since the 1970s." References include Parsons' action theory and Luhmann's social systems theory.

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