System in the context of Mathematical models

The cosmos (/ˈkɒzmɒs/, US also /-moʊs, -məs/; Ancient Greek: κόσμος, romanized: kósmos) is an alternative name for the universe or its nature or order. Usage of the word cosmos implies viewing the universe as a complex and orderly system or entity.

The cosmos is studied in cosmology – a broad discipline covering scientific, religious or philosophical aspects of the cosmos and its nature. Religious and philosophical approaches may include the cosmos among spiritual entities or other matters deemed to exist outside the physical universe.

A design is the concept or proposal for an object, process, or system. The word design refers to something that is or has been intentionally created by a thinking agent, and is sometimes used to refer to the inherent nature of something – its design. The verb to design expresses the process of developing a design. In some cases, the direct construction of an object without an explicit prior plan may also be considered to be a design, such as in arts and crafts. A design is expected to have a purpose within a specific context, typically aiming to satisfy certain goals and constraints while taking into account aesthetic, functional and experiential considerations. Traditional examples of designs are architectural and engineering drawings, circuit diagrams, sewing patterns, and less tangible artefacts such as business process models.

Trade involves the transfer of goods and services from one person or entity to another, often in exchange for money. Economists refer to a system or network that allows trade as a market.

Traders generally negotiate through a medium of credit or exchange, such as money. Though some economists characterize barter (i.e. trading things without the use of money) as an early form of trade, money was invented before written history began. Consequently, any story of how money first developed is mostly based on conjecture and logical inference. Letters of credit, paper money, and non-physical money have greatly simplified and promoted trade as buying can be separated from selling, or earning. Trade between two traders is called bilateral trade, while trade involving more than two traders is called multilateral trade.

A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Physical structures include artifacts and objects such as buildings and machines and natural objects such as biological organisms, minerals and chemicals. Abstract structures include data structures in computer science and musical form. Types of structure include a hierarchy (a cascade of one-to-many relationships), a network featuring many-to-many links, or a lattice featuring connections between components that are neighbors in space.

Biological organization is the organization of complex biological structures and systems that define life using a reductionistic approach. The traditional hierarchy, as detailed below, extends from atoms to biospheres. The higher levels of this scheme are often referred to as an ecological organizational concept, or as the field, hierarchical ecology.

Each level in the hierarchy represents an increase in organizational complexity, with each "object" being primarily composed of the previous level's basic unit. The basic principle behind the organization is the concept of emergence—the properties and functions found at a hierarchical level are not present and irrelevant at the lower levels.

A mathematical model is an abstract description of a concrete system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used in many fields, including applied mathematics, natural sciences, social sciences and engineering. In particular, the field of operations research studies the use of mathematical modelling and related tools to solve problems in business or military operations. A model may help to characterize a system by studying the effects of different components, which may be used to make predictions about behavior or solve specific problems.

An economic system, or economic order, is a system of production, resource allocation and distribution of goods and services within an economy. It includes the combination of the various institutions, agencies, entities, decision-making processes, and patterns of consumption that comprise the economic structure of a given community.

An economic system is a type of social system. The mode of production is a related concept. All economic systems must confront and solve the four fundamental economic problems:

In sociology, a social system is the patterned network of relationships constituting a coherent whole that exist between individuals, groups, and institutions. It is the formal structure of role and status that can form in a small, stable group. An individual may belong to multiple social systems at once; examples of social systems include nuclear family units, communities, cities, nations, college campuses, religions, corporations, and industries. The organization and definition of groups within a social system depend on various shared properties such as location, socioeconomic status, race, religion, societal function, or other distinguishable features.

In the Ottoman Empire, a millet (Turkish: [millet]; Ottoman Turkish: ملت, Arabic: مِلَّة) was an independent court of law pertaining to "personal law" under which a confessional community (a group abiding by the laws of Muslim sharia, Christian canon law, or Jewish halakha) was allowed to rule itself under its own laws.

Despite frequently being referred to as a "system", before the nineteenth century the organization of what are now retrospectively called millets in the Ottoman Empire was not at all systematic. Rather, non-Muslims were simply given a significant degree of autonomy within their own community, without an overarching structure for the millet as a whole. The notion of distinct millets corresponding to different religious communities within the empire would not emerge until the eighteenth century. Subsequently, the millet system was justified through numerous foundation myths linking it back to the time of Sultan Mehmed the Conqueror (r. 1451–81), although it is now understood that no such system existed in the fifteenth century. Heads of millets, or milletbaşı (Ethnarch), usually had absolute secular and ecclesiastical power over their communities, being answerable only to the Sultan.

A world-system is a socioeconomic system, under systems theory, that encompasses part or all of the globe, detailing the aggregate structural result of the sum of the interactions between polities. World-systems are usually larger than single states, but do not have to be global. The Westphalian System is the preeminent world-system operating in the contemporary world, denoting the system of sovereign states and nation-states produced by the Westphalian Treaties in 1648. Several world-systems can coexist, provided that they have little or no interaction with one another. Where such interactions becomes significant, separate world-systems merge into a new, larger world-system. Through the process of globalization, the modern world has reached the state of one dominant world-system, but in human history there have been periods where separate world-systems existed simultaneously, according to Janet Abu-Lughod. The most well-known version of the world-system approach has been developed by Immanuel Wallerstein. A world-system is a crucial element of the world-system theory, a multidisciplinary, macro-scale approach to world history and social change.

Systems theory is the transdisciplinary study of systems, i.e. cohesive groups of interrelated, interdependent components that can be natural or artificial. Every system has causal boundaries, is influenced by its context, defined by its structure, function and role, and expressed through its relations with other systems. A system is "more than the sum of its parts" when it expresses synergy or emergent behavior.

Changing one component of a system may affect other components or the whole system. It may be possible to predict these changes in patterns of behavior. For systems that learn and adapt, the growth and the degree of adaptation depend upon how well the system is engaged with its environment and other contexts influencing its organization. Some systems support other systems, maintaining the other system to prevent failure. The goals of systems theory are to model a system's dynamics, constraints, conditions, and relations; and to elucidate principles (such as purpose, measure, methods, tools) that can be discerned and applied to other systems at every level of nesting, and in a wide range of fields for achieving optimized equifinality.

The balance of power theory in international relations suggests that states may secure their survival by preventing any one state from gaining enough military power to dominate all others. If one state becomes much stronger, the theory predicts it will take advantage of its weaker neighbors, thereby driving them to unite in a defensive coalition. Some realists maintain that a balance-of-power system is more stable than one with a dominant state, as aggression is unprofitable when there is equilibrium of power between rival coalitions.

When threatened, states may seek safety either by balancing, allying with others against the prevailing threat; or bandwagoning, aligning themselves with the threatening power. Other alliance tactics include buck passing and chain-ganging. Realists have long debated how the polarity of a system impacts the choice of tactics; however, it is generally agreed that in bipolar systems, each great power has no choice but to directly confront the other. Along with debates between realists about the prevalence of balancing in alliance patterns, other schools of international relations, such as constructivists, are also critical of the balance of power theory, disputing core realist assumptions regarding the international system and the behavior of states.

In economics, a market is a composition of systems, institutions, procedures, social relations or infrastructures whereby parties engage in exchange. While parties may exchange goods and services by barter, most markets rely on sellers offering their goods or services (including labour power) to buyers in exchange for money. It can be said that a market is the process by which the value of goods and services are established. Markets facilitate trade and enable the distribution and allocation of resources in a society. Markets allow any tradeable item to be evaluated and priced. A market emerges more or less spontaneously or may be constructed deliberately by human interaction in order to enable the exchange of rights (cf. ownership) of services and goods. Markets generally supplant gift economies and are often held in place through rules and customs, such as a booth fee, competitive pricing, and source of goods for sale (local produce or stock registration).

Markets can differ by products (goods, services) or factors (labour and capital) sold, product differentiation, place in which exchanges are carried, buyers targeted, duration, selling process, government regulation, taxes, subsidies, minimum wages, price ceilings, legality of exchange, liquidity, intensity of speculation, size, concentration, exchange asymmetry, relative prices, volatility and geographic extension. The geographic boundaries of a market may vary considerably, for example the food market in a single building, the real estate market in a local city, the consumer market in an entire country, or the economy of an international trade bloc where the same rules apply throughout. Markets can also be worldwide, see for example the global diamond trade. National economies can also be classified as developed markets or developing markets.

Cybernetics is the transdisciplinary study of circular causal processes such as feedback and recursion, where the effects of a system's actions (its outputs) return as inputs to that system, influencing subsequent action. It is concerned with general principles that are relevant across multiple contexts, including in engineering, ecological, economic, biological, cognitive and social systems and also in practical activities such as designing, learning, and managing. Cybernetics' transdisciplinary character has meant that it intersects with a number of other fields, leading to it having both a wide influence and diverse interpretations.

The field is named after an example of circular causal feedback—that of steering a ship (the ancient Greek κυβερνήτης (kybernḗtēs) refers to the person who steers a ship). In steering a ship, the position of the rudder is adjusted in continual response to the effect it is observed as having, forming a feedback loop through which a steady course can be maintained in a changing environment, responding to disturbances from cross winds and tide.

In common usage, evaluation is a systematic determination and assessment of a subject's merit, worth and significance, using criteria governed by a set of standards. It can assist an organization, program, design, project or any other intervention or initiative to assess any aim, realizable concept/proposal, or any alternative, to help in decision-making; or to generate the degree of achievement or value in regard to the aim and objectives and results of any such action that has been completed.

The primary purpose of evaluation, in addition to gaining insight into prior or existing initiatives, is to enable reflection and assist in the identification of future change. Evaluation is often used to characterize and appraise subjects of interest in a wide range of human enterprises, including the arts, criminal justice, foundations, non-profit organizations, government, health care, and other human services. It is long term and done at the end of a period of time.

A supply chain is a complex logistics system that consists of facilities that convert raw materials into finished products and distribute them to end consumers or end customers, while supply chain management deals with the flow of goods in distribution channels within the supply chain in the most efficient manner.

In sophisticated supply chain systems, used products may re-enter the supply chain at any point where residual value is recyclable. Supply chains link value chains. Suppliers in a supply chain are often ranked by "tier", with first-tier suppliers (also called "direct suppliers") supplying directly to the client, second-tier suppliers supplying to the first tier, and so on.

A physical system is a collection of physical objects under study. The collection differs from a set: all the objects must coexist and have some physical relationship.In other words, it is a portion of the physical universe chosen for analysis. Everything outside the system is known as the environment, which is ignored except for its effects on the system.

The split between system and environment is the analyst's choice, generally made to simplify the analysis. For example, the water in a lake, the water in half of a lake, or an individual molecule of water in the lake can each be considered a physical system. An isolated system is one that has negligible interaction with its environment. Often a system in this sense is chosen to correspond to the more usual meaning of system, such as a particular machine.