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,
Kenneth D. Bailey defined systems in terms of
conceptual,
concrete, and abstract systems, either
isolated,
closed, or
open.
Walter F. Buckley defined systems in sociology in terms of
mechanical,
organic, and
process models.
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. 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.
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
unbounded systems, discrete to continuous, pulse to
hybrid systems, etc. The interactions between systems and their environments are categorized as relatively closed and
open systems. 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. 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
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. 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.
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==