The term "systems" is derived from the Greek word "synistanai," which means "to bring together or combine." The term has been used for centuries. Components of the organizational concepts referred to as the "systems approach" have been used to manage armies and governments for millennia. However, it was not until the Industrial Revolution of the 19th and 20th centuries that formal recognition of the "systems" approach to management, philosophy, and science emerged (Whitehead 1925, von Bertalanffy 1968). As the level of precision and efficiency demanded of technology, science, and management increased the complexity of industrial processes, it became increasingly necessary to develop a conceptual basis to avoid being overwhelmed by complexity. The systems approach emerged as scientists and philosophers identified common themes in the approach to managing and organizing complex systems. Four major concepts underlie the systems approach:
Specialization: A system is divided into smaller components allowing more specialized concentration on each component.
Grouping: To avoid generating greater complexity with increasing specialization, it becomes necessary to group related disciplines or sub-disciplines.
Coordination: As the components and subcomponents of a system are grouped, it is necessary to coordinate the interactions among groups.
Emergent properties: Dividing a system into subsystems (groups of component parts within the system), requires recognizing and understanding the "emergent properties" of a system; that is, recognizing why the system as a whole is greater than the sum of its parts. For example, two forest stands may contain the same tree species, but the spatial arrangement and size structure of the individual trees will create different habitats for wildlife species. In this case, an emergent property of each stand is the wildlife habitat.