Systems theory

System theory is a multidisciplinary knowledge model that takes into account the systems to describe and explain different complex phenomena. System theories are often coherent, self-sustaining units, such as " society", " justice " or "household", and explain the observed phenomena by the localization of the phenomenon within the unit. The analysis of structures and functions will often allow predictions about the system behavior. System Theoretical concepts are applied in many scientific disciplines.

Systems theory is both a general and a discipline as well as a widely branched and heterogeneous framework for an interdisciplinary discourse, which introduces the notion of system as a basic concept. Consequently, there is both a general " systems theory " as well as a variety of different, sometimes conflicting and competing system definitions and concepts. It has now, however, a relatively stable set of terms and theorems emerged, referred to by the system-theoretical discourse.

• 1950 General Systems Theory (based on Ludwig von Bertalanffy )

• 1950 Cybernetics ( William Ross Ashby, Warren Sturgis McCulloch, Walter Pitts, Arturo Rosenblueth, Norbert Wiener): Mathematical theory of communication, control and regulation of living, technical and social systems among others related by feedback loops that control theory

• 1970 catastrophe theory: This branch of mathematics describes sudden changes arising from small pulses.

• Around 1980 Chaos Theory: Mathematical theory of non-linear dynamic systems, which describes branches, attractors and chaotic motions.

• Around 1990 Complex Adaptive Systems ( John H. Holland, Murray Gell-Mann, Harold Morowitz, W. Brian Arthur): describes emergence, adaptation, and self-organization, and is based on the work of the Santa Fe Institute.

• 2.1 Chaos Theory
• 2.2 catastrophe theory
• 2.3 connectionism
• 2.4 Modelling
• 2.5 Further

History

The term General system theory goes back to the biologist Ludwig von Bertalanffy. His works, together with cybernetics ( Norbert Wiener, William Ross Ashby ) the basic considerations of this approach to science. Other important theories come from Humberto Maturana and Francisco Varela ( autopoiesis ), Stuart Kauffman ( self-organization ) and Alfred Radcliffe - Brown ( structural functionalism ) and Talcott Parsons ( structural functionalism or systems functionalism ) and Niklas Luhmann ( sociological systems theory ).

Culture History of the concept of system goes back to Johann Heinrich Lambert and was adopted and developed among others by Johann Gottfried Herder. This takes place mainly on the question of how to understand living organisms and their self-preservation and organization.

The modern system theory is based on independently developed approaches that were later synthesized and expanded: The term system theory and system theory comes from Ludwig von Bertalanffy (see " General Systems Theory" ). From Bertalanffy speaks of open systems and developed the concept of organized complexity, which is to describe the dynamic exchange with the environment. Only with the formulation of the concept of information, this concept was, however, continue to generalize. In 1948, Norbert Wiener had with " Cybernetics " ( Cybernetics ) also coined a central expression that is now closely associated with the concept of a system. Another related concept is the Tektologie Alexander Bogdanov.

Cybernetics

Cybernetics treated operationally closed mechanisms. It was designed as a control and communication theory. The focus of cybernetics is to regulate and control. Therefore, in cybernetics come as systems primarily regulated mechanisms into consideration. The scheme is always based on processes that can be described by the mathematical system theory of technique. Bertalanffy has spoken out against the mixing of his system theory and cybernetics, because he considered the mechanistic thinking of cybernetics for the description of life as inadequate.

General extensions of cybernetics

As a system of 2nd order theory is called system theories that are self-referential in the following sense: With the respective systems theory is the system theorist who makes the theory described. The core concept is therefore the observation of the observer.

As Autopoiesis Humberto Maturana refers to both his systems theory as well as the essential process, which he describes in his theory, namely life. Maturana describes, roughly speaking, the same as von Bertalanffy in his system theory, but he argues cybernetic: he speaks of living ( autopoietic ) machines that are operationally closed.

Self-assembly refers to processes that lead as autopoiesis to higher structural systems without a controlling element is visible. One example is the laser beam, under which the theory of H. Haken was also developed.

Radical constructivism was developed by Ernst von Glasersfeld. He has resorted to doing the work of Jean Piaget. The mindset of Piaget was a constructivist and epistemologically. Ernst von Glasersfeld argues especially with the operational coherence of systems.

As a System Dynamics is called modeling with control loops. Made famous Jay Wright Forrester, the process by the world model " World3 " by which the " Club of Rome " Limits to Growth publication ( The Limits to Growth, Dennis L. Meadows, 1972), the global commodity consumption was forecasted.

Sociological systems theory

The sociological systems theory sees itself as a universal theory in the sense of a complete and coherent theory building for all forms of sociality. The sociological concept of system goes back to Talcott Parsons. Parsons considered it acts as a constitutive element of social systems. He coined the term structural- functional systems theory.

Niklas Luhmann extends the theory of Parsons and no longer uses the concept of action, but the much more general concept of operation - see system theory ( Luhmann).

Theory of Complex Systems

The latest flow is the theory of complex systems. A complex system is a system whose properties can not be fully explained by the properties of the components of the system. Complex systems consist of a plurality of interconnected and interacting parts, entities or agents.

The theory of complex adaptive systems based mainly on the work of the Santa Fe Institute. This new complexity theory, emergence, adaptation, and self-organization describes is based on agents and computer simulations, the multi-agent systems (MAS ) involve that have become an important tool in the study of social and complex systems.

Related areas

These four main directions have precursors, subdivisions, developments, applications in the medical fields.

Chaos theory

The chaos theory deals with certain nonlinear dynamical systems that have a number of phenomena that one Chaos: calls (specifically chaotic behavior ). One such phenomenon is the butterfly effect, which states that small changes can have unexpectedly large effects. Chaotic systems are, for example, weather, climate, plate tectonics, turbulent flows, economic cycles, Internet and population growth.

Catastrophe theory

Catastrophe theory is a branch of mathematics that deals with the ramifications of dynamical systems and describes sudden changes that result from small changes in circumstances.

Connectionism

The connectionism is understood as a system of networked interactions of many simple units. Most connectionist models describe the information processing in neural networks. They form a bridge between biological research and technical application.

Modeling

In order to describe systems in models, areas of mathematics and computer science play a role. If a system can be described quantitatively and other conditions are met (in particular the differentiability of the descriptive functions), systems of differential equations for mathematical modeling are often used. Absence of these conditions, then the description must be made on a more abstract level. For a formal description with conceptual means used in mathematics, the formal concept analysis, a branch of order theory. On the computer science side, the ontology ( computer science ) busy trying to describe systems formally with conceptual means. Foundations for this are also in the philosophical ontology.

More

• System Theory in Engineering
• Systemic Psychology
• Systemic social work
• Systemic Therapy
• Systems theory of evolution
• Viable Systems Theory
• Theory of dissipative systems: Ilya Prigogine