See also:
From Wikipedia c. 07-Apr-2012
A system (from Latin systēma, in turn from Greek σύστημα systēma, “whole compounded of several parts or members, system”, literary “composition”) is a set of interacting or interdependent components forming an integrated whole.
A system is a set of elements (often called ‘components’ instead) and relationships which are different from relationships of the set or its elements to other elements or sets.
Fields that study the general properties of systems include systems theory, cybernetics, dynamical systems, thermodynamics and complex systems. 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.
Most systems share common characteristics, including:
Systems have structure, defined by components/elements and their composition;
Systems have behavior, which involves inputs, processing and outputs of material, energy, information, or data;
Systems have interconnectivity: the various parts of a system have functional as well as structural relationships to each other.
Systems may have some functions or groups of functions
The term system may also refer to a set of rules that governs structure and/or behavior.
My Own Writing
We live in a world of systems, collections of interacting things. But this isn’t always apparent to people. It takes a higher-level perspective to see what’s happening, to realize there are feedback loops: there are self-perpetuating cycles and self-regulating cycles all around around us, that a systems theorist can see. For example, in American foreign policy, the more we try to impose our will by force, the more resentment and resistance and terrorist acts we provoke. Or look at the endless loop of violence between Israelis and Palestinians. Or take the case of traffic: as residential development occurs, traffic increases. But building more road capacity allows more development to occurs, which worsens traffic again. Like a lot of cycles in the modern world, it’s self-perpetuating and thus not sustainable because they eventually reach a crisis point. The natural world is full of cycles, usually self-regulating cycles. The Greenhouse Effect will feed on itself as more heat is held in the atmosphere. The important thing to realize is that all cycles are happening simultaneously, at different scales, all around us: chemical, physical, biological, social, political, personal, economic. There are cycles of the economy, of the day, the week, the month, the year. There are cycles within your own body: sleep, etc. Some are just rhythms. It’s a perspective for viewing everything–the systems perspective.
We live in a world of systems: computer systems, network systems, transportation systems, communication systems, political systems, social systems, ecological systems. So it makes sense to learn the principles that apply to systems.
The more interacting elements of a system, the more difficult it is to model and thus predict the behavior of.
To understand the tree, you must understand the forest. To understand the forest, you must understand the tree.
Successful systems tend to expand until they reach a point where they begin to fail.
Patterns can be abstracted into principles and principles, when applied, result in patterns.
Systems must be kept simple in order to be modeled. Only by modeling can the effect of changes to the structure or contents of a system be predicted. So predictability of the effect of changes is a benefit of simplicity.
You cannot predict small scale-changes (e.g. time: daily stock price movements, human behavior: an individual’s daily actions), but you can predict large-scale changes (e.g long-term stock price trends, social changes).
Any system that works will have increasingly greater demands placed upon it until it breaks.
Processes create structures and structures create processes.
Things must often get worse before they can get better.
Each extreme creates its opposite.
Even complex dynamic systems with multiple feedback loops can be understood and improved.
Systems Principles
“Playing the game changes the game.”