From Wikipedia, the free encyclopedia
A system is a set of interacting or interdependent components forming an integrated whole.
Every system is delineated by its spatial and temporal boundaries, surrounded and influenced by its environment, described by its structure and purpose and expressed in its functioning.
Fields that study the general properties of systems include systems science,systems theory, systems modeling,systems engineering, cybernetics,dynamical systems, thermodynamics,complex systems, system analysis and design and systems architecture. They investigate the abstract properties of systems’ matter and organization, looking for concepts and principles that are independent of domain, substance, type, or temporal scale.
Some systems share common characteristics, including:
- A system has structure, it contains parts (or components) that are directly or indirectly related to each other;
- A system has behavior, it exhibits processes that fulfill its function or purpose;
- A system has interconnectivity: the parts and processes are connected by structural and/or behavioral relationships.
- A system’s structure and behavior may be decomposed via subsystems and sub-processes to elementary parts and process steps.
- A system has behavior that, in relativity to its surroundings, may be categorized as both fast and strong
The term system may also refer to a set of rules that governs structure and/or behavior. Alternatively, and usually in the context of complex social systems, the term institution is used to describe the set of rules that govern structure and/or behavior.
Environment and boundaries
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 thestructure and/or the 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 outputs can be interpreted as purposes. Human-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.
An open system exchanges matter and energy with its surroundings. Most systems are open systems; like a car, coffeemaker, or computer. Aclosed system exchanges energy, but not matter, with its environment; like Earth or the project Biosphere2 or 3. An isolated system exchanges neither matter nor energy with its environment. A theoretical example of such system is the Universe.
Open system have input and output flows, representing exchanges of matter, energy or information with its surroundings.
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 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.
A subsystem is a set of elements, which is a system itself, and a component of a larger system.
A system comprises multiple views. For the man-made systems it may be such views as concept, analysis, design, implementation, deployment, structure, behavior, input data, and output data views. A system model is required to describe and represent all these multiple views.
A systems architecture, using one single integrated model for the description ofmultiple views such as concept, analysis, design, implementation, deployment, structure, behavior, input data, and output data views, is a kind of system model.