What is Complex System

A complex system has many elements involved in non-linear interactions, making precise predictions impossible.

(1) A system that constantly evolve and unfolded over time (Arthur, 2000 AU17: The in-text citation "Arthur, 2000" is not in the reference list. Please correct the citation, add the reference to the list, or delete the citation. ). (2) A system with multiple elements adapting or reacting to the pattern these elements create (Arthur, 2000 AU18: The in-text citation "Arthur, 2000" is not in the reference list. Please correct the citation, add the reference to the list, or delete the citation. ). (3) A system in which the information-processing capacities of agents are limited relative to the information available to them ( Moss & Rae, 1992 ).

An emerging discipline of science that involves the analysis of the interaction and behavior of sub parts of a system and its elementary constituents together with the collective system which govern in the emergence of patterns of behavior demonstrating non- linear dynamics. It aids in understanding how interactions of the components with its environment result in the rise of patterns by quantification of its variables and parameters. It encompasses disciplines of science and biological systems, engineering, and management. The emergent behavior demonstrated is neither completely ordered and predictable, nor completely random and unpredictable. These systems generate patterns and hierarchy of structures that emerge due to its attractor.

A typical complex system consists of a vast number of identical copies of several generic processes, which are operating and interacting only locally or with a limited number of not necessary close neighbours. There is no global leader or controller associated to such systems and the resulting behaviour is usually very complex.

A complex system means a system whose perceived complicated behaviors can be attributed to one or more of the following characteristics: large number of element, large number of relationships among elements, non-linear and discontinuous relationship, and uncertain characteristics of elements.

A system characterized by the number of the elements that constitute it, and by the nature of the interactions between these elements.

A system having multiple components and sub-components making it difficult to evaluate its performance.

System made up of many interconnected elements on various levels; interactions on lower levels give rise to events on higher levels.

A system that exhibits a mutual interdependency of components and for which a change in the input parameter(s) can result in a non-proportional large or small change of the system output.

A system which is usually composed of large number of possibly heterogeneous interacting agents, which are seen to exhibit emergent behavior. Emergence implies that system level behavior (macro level) cannot be inferred from observation of individual level behavior of its constituents (micro level). This absence of explicit links between the micro and macro levels makes complex systems especially difficult to analyze using traditional statistical and analytical techniques to study the dynamics of behavior. One typically requires the use of bottom up simulation based methods to study such systems. Complex systems are ubiquitous – markets, societies, social networks, the Internet, weather, ecosystems, are just a few examples.

A collection of interrelated elements organized to accomplish a specific function or a set of functions. Complexity can be considered in terms of a number of elements and/or complexity of relationships.

It is the relationship that occurs between the set of events that are represented by variables and parameters, that interacting and growing in events shapes the complexity of organizations and allows to exploit more information for decision making in different situations.

A system whose intricacy impedes the forecasting of its behaviour.

A highly coupled system where the outcomes of the system are the result of the interactions that occur between its different components.