:''For the Macintosh operating system, which was called
System up to version 7.5.5, see
Mac OS.''
A
system is an assemblage of inter-related elements comprising a unified whole. From the Latin and Greek, the term "system" meant to combine, to set up, to place together. A
sub-system is a system which is part of another system.
A system typically consists of
components (or
elements) which are connected together in order to facilitate the flow of
information,
matter or
energy. The term is often used to describe a
set of entities which interact, and for which a
mathematical model can often be constructed.
Background
At arbitrary boundaries, a collection of interrelated components may be declared a system and may further be abstracted to be declared a component of a larger system. Systems enable "activities" to be performed. (It is tempting to say that systems enable "things" to be done—but that is confusing in this context). An
engineering example of a system is often a
circuit or a physical series.
Depending on the type of system, a system can often be distinguished from individual
machines,
elements or
processes of that system by the number, arrangements and complexity of those elements. For example, a
pulley is a
machine, but an
elevator, which incorporates pulleys (amongst other components), is a
system. Going to the
doctor is a
process, but
health care is a
system.
In the natural world, we say that there are systems. For example, the
solar system of nine planets orbiting the sun. In the human body, we refer to such systems as the
nervous system, the
circulatory system, the digestive system, the reproductive system, and the
respiratory system.
In addition, all so-called "things" (
Objects) are actually systems. For example, a cup is an object, but it is also a system for holding hot or cold liquid, or other material. The cup has a certain shape and a handle, it is made of non-porous material and so on, and it is put together in such a way as to provide a useful function. Describing this thing makes up information, and defines a system.
Types of systems
An
open system can be influenced by events outside of the declared boundaries of a system. A
closed system is self-contained: outside events can have no influence upon the system. In practice many things are a mixture of the two. For example a prison is a closed system because the prisoners can't get out, and the wardens spend most of their time at the prison. However it is also an open system, because it depends on outside factors and the prisoners and wardens do go outside.
Dynamic systems have components or flows or both, that change over time.
Another distinction is the relation of
physical systems to
conceptual systems. Physical systems are systems of matter and energy. Conceptual systems are made up of ideas. Conceptual systems generally exist to aid in the accomplishment of specific goals or may be used to model physical systems.
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 to run, see
platform.
Systems in operations research and management science
In
operations research and
organizational development (OD), organizations are viewed as human
systems (conceptual systems) of interacting components such as sub-systems, processes and organizational structures. Organizational development theorist
Peter Senge developed the notion of organizations as systems in his book
The Fifth Discipline.
Systems thinking has been identified as an important leadership competency where an individual thinks globally when acting locally. Such person takes into account the potential consequences of a decision on other parts of the organization.
Organizational theorists such as
Margaret J. Wheatley have also described the workings of organizational systems in new contexts, such as quantum physics,
chaos theory, and the self-organization of systems.
See also
External links
Category:Cybernetics
Category:Systems theory
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