A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole.
Systems have several common properties and characteristics, including structure, function(s), behavior and interconnectivity.
Etymology
The term
system comes from the
Latin word
systēma, in turn from
Greek language σύστημα
systēma: "whole concept made of several parts or members, system", literary "composition".
[ "σύστημα" , Henry George Liddell, Robert Scott, A Greek–English Lexicon, on Perseus Digits Library.][ Definitionen von "System" (1572–2002) by Roland Müller, (most in German).]
History
In the 19th century, the French physicist Nicolas Léonard Sadi Carnot, who studied
thermodynamics, pioneered the development of the concept of a
system in the
. In 1824, he studied the system which he called the
working substance (typically a body of water vapor) in
, in regard to the system's ability to do work when heat is applied to it. The working substance could be put in contact with either a boiler, a cold reservoir (a stream of cold water), or a piston (on which the working body could do work by pushing on it). In 1850, the German physicist
Rudolf Clausius generalized this picture to include the concept of the surroundings and began to use the term
working body when referring to the system.
The biologist Ludwig von Bertalanffy became one of the pioneers of the general systems theory. In 1945 he introduced models, principles, and laws that apply to generalized systems or their subclasses, irrespective of their particular kind, the nature of their component elements, and the relation or 'forces' between them.[1945, Zu einer allgemeinen Systemlehre, Blätter für deutsche Philosophie, 3/4. (Extract in: Biologia Generalis, 19 (1949), 139–164.]
In the late 1940s and mid-50s, Norbert Wiener and Ross Ashby pioneered the use of mathematics to study systems of Control system and communication, calling it cybernetics.[
1948, Cybernetics: Or the Control and Communication in the Animal and the Machine. Paris, France: Librairie Hermann & Cie, and Cambridge, MA: MIT Press.Cambridge, MA: MIT Press.][1956. An Introduction to Cybernetics , Chapman & Hall.]
In the 1960s, Marshall McLuhan applied general systems theory in an approach that he called a field approach and figure/ground analysis, to the study of media theory.
In the 1980s, John Henry Holland, Murray Gell-Mann and others coined the term complex adaptive system at the interdisciplinary Santa Fe Institute.
Concepts
Environment and boundaries
Systems theory views the world as a
complex system of interconnected parts. One scopes a system by defining its boundary; this means choosing which
entities are inside the system and which are outside—part of the environment. One can make simplified representations (models) of the system in order to understand it and to predict or impact its future behavior. These models may define the structure and behavior of the system.
Natural and human-made systems
There are natural and human-made (designed) systems. Natural systems may not have an apparent objective but their behavior can be interpreted as purposeful by an observer. Human-made systems are made with various purposes that are achieved by some action performed by or with the system. The parts of a system must be related; they must be "designed to work as a coherent entity"—otherwise they would be two or more distinct systems.
Theoretical framework
Most systems are open systems, exchanging matter and energy with their respective surroundings; like a car, a
coffeemaker, or
Earth. A
closed system exchanges energy, but not matter, with its environment; like a computer or the project Biosphere 2. An
isolated system exchanges neither matter nor energy with its environment. A theoretical example of such a system is the
Universe.
Process and transformation process
An open system can also be viewed as a bounded transformation process, that is, a
black box that is a process or collection of processes that transform inputs into outputs. Inputs are consumed; outputs are produced. The concept of input and output here is very broad. For example, an output of a passenger ship is the movement of people from departure to destination.
System model
A system comprises
view model. Human-made systems may have such views as concept,
systems analysis,
Systems design,
implementation, deployment, structure, behavior, input data, and output data views. A
system model is required to describe and represent all these views.
Systems architecture
A systems architecture, using one single integrated model for the description of multiple views, is a kind of system model.
Subsystem
A
subsystem is a set of elements, which is a system itself, and a component of a larger system. The IBM Mainframe
Job Entry Subsystem family (JES1, JES2, JES3, and their HASP/ASP predecessors) are examples. The main
elements they have in common are the components that handle input, scheduling, spooling and output; they also have the ability to interact with local and remote operators.
A subsystem description is a system object that contains information defining the characteristics of an operating environment controlled by the system.
Analysis
There are many kinds of systems that can be analyzed both
quantitatively and qualitatively. For example, in an analysis of urban
systems dynamics, A . W. Steiss defined five intersecting systems, including the physical subsystem and behavioral system. For sociological models influenced by systems theory,
[Steiss, 1967, pp. 8–18.] Kenneth D. Bailey defined systems in terms of conceptual, concrete, and abstract systems, either
Isolated system,
Closed system, or open.
[Bailey, 1994.] Walter F. Buckley defined systems in sociology in terms of
Mechanics, organic, and
.
[Buckley, 1967.] Bela H. Banathy cautioned that for any inquiry into a system understanding its kind is crucial, and defined
natural and
designed, i. e. artificial, systems.
[Banathy, 1997.] For example, natural systems include
subatomic systems,
living systems, the
Solar System,
galaxies, and the
Universe, while artificial systems include man-made physical structures, hybrids of natural and artificial systems, and conceptual knowledge. The human elements of organization and functions are emphasized with their relevant abstract systems and representations.
Artificial systems inherently have a major defect: they must be premised on one or more fundamental assumptions upon which additional knowledge is built. This is in strict alignment with Gödel's incompleteness theorems. The Artificial system can be defined as a "consistent formalized system which contains elementary arithmetic".[K.Gödel, 1931.] These fundamental assumptions are not inherently deleterious, but they must by definition be assumed as true, and if they are actually false then the system is not as structurally integral as is assumed (i.e. it is evident that if the initial expression is false, then the artificial system is not a "consistent formalized system"). For example, in geometry this is very evident in the postulation of and extrapolation of proofs from them.
George J. Klir maintained that no "classification is complete and perfect for all purposes", and defined systems as abstract, real, and conceptual physical systems, bounded and , discrete to continuous, pulse to , etc. The interactions between systems and their environments are categorized as relatively closed and open systems.[Klir, 1969, pp. 69–72.] Important distinctions have also been made between hard systems—–technical in nature and amenable to methods such as systems engineering, operations research, and quantitative systems analysis—and soft systems that involve people and organizations, commonly associated with concepts developed by Peter Checkland and Brian Wilson through soft systems methodology (SSM) involving methods such as action research and emphasis of participatory designs.[Checkland, 1997; Flood, 1999.] Where hard systems might be identified as more scientific, the distinction between them is often elusive.
Economic system
An economic system is a social institution which deals with the production, distribution and consumption of
goods and services in a particular
society. The economic system is composed of
person,
institutions and their relationships to resources, such as the convention of
property. It addresses the problems of
economics, like the allocation and scarcity of resources.
The international sphere of interacting states is described and analyzed in systems terms by several international relations scholars, most notably in the neorealist school. This systems mode of international analysis has however been challenged by other schools of international relations thought, most notably the constructivist school, which argues that an over-large focus on systems and structures can obscure the role of individual agency in social interactions. Systems-based models of international relations also underlie the vision of the international sphere held by the liberal institutionalist school of thought, which places more emphasis on systems generated by rules and interaction governance, particularly economic governance.
Information and computer science
In
computer science and information science, an information system is a hardware system,
software system, or combination, which has components as its structure and observable inter-process communications as its behavior.
There are systems of counting, as with Roman numerals, and various systems for filing papers, or catalogs, and various library systems, of which the Dewey Decimal Classification is an example. This still fits with the definition of components that are connected together (in this case to facilitate the flow of information).
System can also refer to a framework, aka platform, be it software or hardware, designed to allow software programs to run. A flaw in a component or system can cause the component itself or an entire system to fail to perform its required function, e.g., an incorrect statement or data definition.
Engineering and physics
In
engineering and
physics, a physical system is the portion of the universe that is being studied (of which a thermodynamic system is one major example). Engineering also has the concept of a system referring to all of the parts and interactions between parts of a complex project. Systems engineering is the branch of engineering that studies how this type of system should be planned, designed, implemented, built, and maintained.
Sociology, cognitive science and management research
Social and cognitive sciences recognize systems in models of individual humans and in human societies. They include human brain functions and mental processes as well as normative ethics systems and social and cultural behavioral patterns.
In management science, operations research and organizational development, human organizations are viewed as management systems of interacting components such as subsystems or system aggregates, which are carriers of numerous complex business processes (organizational behaviors) and organizational structures. Organizational development theorist Peter Senge developed the notion of organizations as systems in his book The Fifth Discipline.
Organizational theorists such as Margaret Wheatley have also described the workings of organizational systems in new metaphoric contexts, such as quantum physics, chaos theory, and the self-organization of systems.
Pure logic
There is also such a thing as a
logical system. An obvious example is the calculus developed simultaneously by
Leibniz and
Isaac Newton. Another example is
George Boole's Boolean operators. Other examples relate specifically to philosophy, biology, or cognitive science. Maslow's hierarchy of needs applies psychology to biology by using pure logic. Numerous psychologists, including
Carl Jung and
Sigmund Freud developed systems that logically organize psychological domains, such as personalities, motivations, or intellect and desire.
Strategic thinking
In 1988, military strategist John A. Warden III introduced the Five Ring System model in his book,
The Air Campaign, contending that any complex system could be broken down into five concentric rings. Each ring—leadership, processes, infrastructure, population and action units—could be used to isolate key elements of any system that needed change. The model was used effectively by
Air Force planners in the Iran–Iraq War.
In the late 1990s, Warden applied his model to business strategy.
See also
Bibliography
External links
