r of its parts may be measured and controlled. The behavior within such a system "consists of a set of interdependent acts which constitute an operation" (Ackoff, 1986, p. 332).
Systems may be either closed or open. A closed system is one which does not depend on its environment; it is autonomous, enclosed, and sealed off from the outside world (Broderick and Smith, 1979). It has all the energy it needs, and can function without the consumption of external resources. By contrast, an open system is one which must interact with its environment to survive; it both consumes resources and exports resources to the environment (Broderick and Smith, 1979). It must continually change and adapt to the environment. Open systems require information input, negative feedback, and a coding process. Without negative feedback, a system's steady state vanishes, its boundaries disappear, and the system dies (Miller, 1955). Families are open systems (Casey, 1989).
A person is an individual behavioral system (Fawcett, 1989), which, in turn, is a component of the larger family behavioral system. For individuals and for families, the external environment includes all forces (object, events, and situations) which are capable of impinging on either the individual or the family. For individuals, the internal environment involves the psychological and physical characteristics of the individual which permit and facilitate reaction and adjustment to external forces, which include the family system. For families, the internal environment involves the psychological and physical characteristics of the family as a whole which permit and facilitate reaction and adjustment to external forces.
Behavioral system balance within a family is a manifestation of successful adjustments and adaptations, even though observed behavior may not appear to be consistent with accepted cultural or biologic norms for healthy behavior (Johnson, 1...