There are many ways to view organizations, so researchers, professors, and students need some structure and guidance to aid discussions on the topic. Organization theory offers a structured way to talk about the organization as a unit and the subunits, groups, and individuals who work within an organization. Organizations and the people who work in them are the focus of study in organization theory. There are many different “models” used to represent organizations, and one that is currently used is called the contingency model, meaning different organizations types are likely to be most effective in different situations. Researchers in business administration, psychology, and sociology conduct studies of individuals and groups in organizations, the purpose of which is to attempt to identify typical behavior patterns. The focus may be on the total organization, groups of employees such as departments or divisions, or on individual employees. Other topics of research related to organization theory include ORGANIZATION BEHAVIOR, HUMAN RESOURCES management and organization development. The primary differences relate to the level of analysis and the focus on either theory or practice. In organization behavior, the level of analysis mainly concerns the group and the individual rather than the total organization, and the focus is on theory. Both human resources management and organization development focus on application to real situations (practice). Human resources management emphasizes the individual level of analysis, while organization development works at the level of the full organization or large groups within the organization. One key aspect of modern organizational theory is the emphasis on the environment in which the organization operates, which is often referred to in terms of a systems approach. This general frame of reference comes from biology and can be applied to organizations in a purely theoretical way. In the early days of study and research on organizations, managers and even researchers took what may be termed a closed-system approach, meaning they tried to consider only those aspects of the organization itself in relation to its functioning and success or failure. They seldom tried to evaluate the environmental influences on the organization or vice versa. The newer approach, called the open-systems view, makes it clear that organizations can only be studied in terms of how they interact with their environment. There are many aspects of the environment to consider; for instance, there is the immediate community in which the organization operates for such important factors as the labor market; and there are also the variables in the organizations’ own industries, such as competitors, suppliers and technical specialty organizations. All of these entities will be influenced by and will likewise influence the organization. In order to make sense of the organization and its operation, factors from the environment must be included, and thus an open-systems view is essential to current understanding of organization theory. Effectiveness in organization functioning may be measured in many different ways. The traditional methods focus on productivity, quality, and earnings for private organizations. Some newer and more widely focused methods of measuring success include the satisfaction of both customers and employees, the organization’s STAKEHOLDERS, and the actual stockholders and BOARD OF DIRECTORS. Others who might be considered when viewing the organization’s environment would include bankers who lend money to the organization and might view it in terms of its success in maintaining credit. Suppliers might add the view that payment of invoices is a measure of success. This type of extension of the way organizations are viewed is a factor that has developed in the way organization theory has grown as a study specialty. Organization theory is often used to study the ways that organizations sets goals and then plan how to meet those goals. This focus is generally called STRATEGIC PLANNING or strategic MANAGEMENT. These are primarily internal factors but are clearly influenced by external variables such as COMPETITION; general economic factors (for example, INTEREST RATES); and, for international organizations, TRADE BALANCEs with other countries.