ABSTRACT
As quoted in Dent and Blackie (1979), system concepts consider the multidisciplinary approach. A system consists of many elements. These elements make up the system. To understand the complex system, a set of studies of the various elements separately is essential. The whole of the system is more complex than the sum of the indiv idual parts. One should define the precise locat ion of the system's boundary . The environment outside the boundary of the system is uncertain and difficult to predict. Inside the boundary, the modeler can perceive a hierarchial structure of subsystems and sub-subsystems of the major system under study. Thus, the subsystems are considered to interact only through their act of joining in a higher system.
