Jump to content

System: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
m Reverted edits by 59.90.162.24 to last version by 12.149.182.130 (HG)
Line 28: Line 28:


== System concepts ==
== System concepts ==
;Environment and boundaries
;Environment and boundaries bnvbnvbbbnvbn
:[[Systems theory]] views the world as a complex system of interconnected parts. We scope a system by defining its ''boundary''; this means choosing which entities are inside the system and which are outside - part of the ''environment''. We then 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/or the [[behaviour]] of the system.
:[[Systems theory]] views the world as a complex system of interconnected parts. We scope a system by defining its ''boundary''; this means choosing which entities are inside the system and which are outside - part of the ''environment''. We then 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/or the [[behaviour]] of the system.



Revision as of 14:41, 3 September 2008

A schematic representation of a closed system and its boundary

System (from Latin systēma, in turn from Greek σύστημα systēma) is a set of interacting or interdependent entities, real or abstract, forming an integrated whole.

The concept of an "integrated whole" can also be stated in terms of a system embodying a set of relationships which are differentiated from relationships of the set to other elements, and from relationships between an element of the set and elements not a part of the relational regime.

Overview

The scientific research field which is engaged in the transdisciplinary study of universal system-based properties of the world is general system theory, systems science and recently systemics. They investigate the abstract properties of the matter and mind, their organization, searching concepts and principles which are independent of the specific domain, independent of their substance, type, or spatial or temporal scales of existence.

The term system has multiple meanings [1]:

  1. A collection of organized things; as, a solar system.
  2. A way of organizing or planning.
  3. A whole composed of relationships among the members.

Most systems share the same common characteristics. These common characteristics include the following:[2]

  1. Systems have a structure that is defined by its parts and processes.
  2. Systems are generalizations of reality.
  3. Systems tend to function in the same way. This involves the inputs and outputs of material (energy and/or matter) that is then processed causing it to change in some way.
  4. The various parts of a system have functional as well as structural relationships between each other.

The characteristics of systems have been studied in general systems theory.

History

The term System has a long history which can be traced back to the Greek language.

In the 19th century the first to develop the concept of a "system" in the natural sciences was the French physicist Sadi Carnot who studied thermodynamics. In 1824 he studied what he called the working substance (system), i.e. typically a body of water vapor, in steam engines, in regards 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 heat reservoir (a boiler), a cold reservoir (a stream of cold water), or a piston (to 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.

In the 1980s the term complex adaptive system was coined at the interdisciplinary Santa Fe Institute by John H. Holland, Murray Gell-Mann and others.

System concepts

Environment and boundaries bnvbnvbbbnvbn
Systems theory views the world as a complex system of interconnected parts. We scope a system by defining its boundary; this means choosing which entities are inside the system and which are outside - part of the environment. We then 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/or the behaviour of the system.
Natural and man-made systems
There are natural and man-made (designed) systems. Natural systems may not have an apparent objective but their outputs can be interpreted as purposes. Man-made systems are made with purposes that are achieved by the delivery of outputs. Their parts must be related; they must be “designed to work as a coherent entity” - else they would be two or more distinct systems
Open system
An open system usually interacts with some entities in their environment. A closed system is isolated from its environment.
Process and transformation process
A system can also be viewed as a bounded transformation process, that is, a process or collection of processes that transforms inputs into outputs. Inputs are consumed; outputs are produced. The concept of input and output here is very broad. E.g. An output of a passenger ship is the movement of people from departure to destination.
Subsystem
A subsystem is a set of elements, which is a system itself, and a part of a larger system.

Types of systems

Evidently, there are many types of systems that can be analyzed both quantitatively and qualitatively. For example, with an analysis of urban systems dynamics, [A.W. Steiss] [3] defines five intersecting systems, including the physical subsystem and behavioral system. For sociological models influenced by systems theory, where Kenneth D. Bailey [4] defines systems in terms of conceptual, concrete and abstract systems; either isolated, closed, or open, Walter F. Buckley [5] defines social systems in sociology in terms of mechanical, organic, and process models. Bela H. Banathy [6] cautions that with any inquiry into a system that understanding the type of system is crucial and defines Natural and Designed systems.

In offering these more global definitions, the author maintains that it is important not to confuse one for the other. The theorist explains that natural systems include sub-atomic systems, living systems, the solar system, the galactic system and the Universe. Designed systems are our creations, our physical structures, hybrid systems which include natural and designed systems, and our conceptual knowledge. The human element of organization and activities are emphazized with their relevant abstract systems and representations. A key consideration in making distinctions among various types of systems is to determine how much freedom the system has to select purpose, goals, methods, tools, etc. and how widely is the freedom to select distributed (or concentrated) in the system.

George J. Klir [7] maintains that no "classification is complete and perfect for all purposes," and defines systems in terms of abstract, real, and conceptual physical systems, bounded and unbounded systems, discrete to continuous, pulse to hybrid systems, et cetera. The interaction between systems and their environments are categorized in terms of absolutely closed systems, relatively closed, and open systems. The case of an absolutely closed system is a rare, special case. Important distinctions have also been made between hard and soft systems.[8] Hard systems are associated with areas such as systems engineering, operations research and quantitative systems analysis. Soft systems are commonly associated with concepts developed by Peter Checkland through Soft Systems Methodology (SSM) involving methods such as action research and emphasizing participatory designs. Where hard systems might be identified as more "scientific," the distinction between them is actually often hard to define.

Cultural system

A cultural system may be defined as the interaction of different elements of culture. While a cultural system is quite different from a social system, sometimes both systems together are referred to as the sociocultural system. A major concern in the social sciences is the problem of order. One way that social order has been theorized is according to the degree of integration of cultural and social factors.

Economic system

An economic system is a mechanism (social institution) which deals with the production, distribution and consumption of goods and services in a particular society. The economic system is composed of people, 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.

Application of the system concept

Generally systems modeling is a basic principle in engineering and in social sciences. The system is the representation of the entities under concern. Hence inclusion to or exclusion from system context is dependent of the intention of the modeler.

No model of a system will include all features of the real system of concern, and no model of a system must include all entities belonging to a real system of concern.

Systems in information and computer science

In computer science and information science, system could also be a method or an algorithm. Again, an example will illustrate: There are systems of counting, as with Roman numerals, and various systems for filing papers, or catalogues, and various library systems, of which the Dewey Decimal System is an example. This still fits with the definition of components which are connected together (in this case in order to facilitate the flow of information).

System can also be used referring to a framework, be it software or hardware, designed to allow software programs to run, see platform.

Systems in engineering

In engineering, the concept of a system is usually well defined. It is used in numerous different concrete contexts, and it is the subject of the basic engineering activities, such as: planning, design, implementation, building, and maintaining. Systems engineering is also a generalized theoretical branch of the different engineering approaches and paradigms.

Systems in social and cognitive sciences and management research

Social and cognitive sciences recognize systems in human person models and in human societies. They include human brain functions and human mental processes as well as normative ethics systems and social/cultural behavioral patterns.

In management science, operations research and organizational development (OD), human organizations are viewed as systems (conceptual systems) of interacting components such as subsystems or system aggregates, which are carriers of numerous complex processes and organizational structures. Organizational development theorist Peter Senge developed the notion of organizations as systems in his book The Fifth Discipline.

Systems thinking is a style of thinking/reasoning and problem solving. It starts from the recognition of system properties in a given problem. It can be a leadership competency. Some people can think globally while acting locally. Such people consider the potential consequences of their decisions on other parts of larger systems. This is also a basis of systemic coaching in psychology.

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.

In modern systemic socio-cognitive engineering the concept system is generalized to so-called intelligence-based systems. The Top-down Object-based Goal-oriented Approach (TOGA meta-theory) integrates formally the concepts of system, process, function and goal in frame of one congruent conceptualization meta-system. Among others, this paradigm enables the computational analysis of heterogeneous human-organization-technology aggregates and recognition of their pathological properties such as organization vulnerability, crisis and changes [9].

See also

Template:Multicol

Examples of systems

Template:Multicol-break

Theories about systems

Template:Multicol-break

Other related topics

Template:Multicol-end

References

  1. ^ Wiktionary:system
  2. ^ [Michael Pidwirny], Definitions of Systems and Models, 1999-2007.
  3. ^ Steiss 1967, p.8-18.
  4. ^ Bailey, 1994.
  5. ^ Buckley, 1967.
  6. ^ Banathy, 1997.
  7. ^ Klir 1969, pp. 69-72
  8. ^ Checkland 1997; Flood 1999.
  9. ^ Adam Maria Gadomski, Modeling of socio-cognitive vulnerability - TOGA meta-theory approach *, International Workshop on Complex Network and Infrastructure Protection, CNIP2006, Rome

Further reading

  • Alexander Backlund (2000). "The definition of system". In: Kybernetes Vol. 29 nr. 4, pp. 444-451.
  • Kenneth D. Bailey (1994). Sociology and the New Systems Theory: Toward a Theoretical Synthesis. New York: State of New York Press.
  • Bela H. Banathy (1997). "A Taste of Systemics", ISSS The Primer Project.
  • Walter F. Buckley 91967). Sociology and Modern Systems Theory, New Jersey: Englewood Cliffs.
  • Peter Checkland (1997). Systems Thinking, Systems Practice. Chichester: John Wiley & Sons, Ltd.
  • Robert L. Flood (1999). Rethinking the Fifth Discipline: Learning within the unknowable. London: Routledge.
  • George J. Klir (1969). Approach to General Systems Theory, 1969.