All systems are located in space and time of a certain environment. The system exchanges material, energy and information with the external environment. The performance of a system depends upon its internal structure and function on the one side, and also depends upon its active adaption to its external environment on the other side. Moreover, the system also has impact to the environment where it is existed. It should be emphasized that the relationship between system and environment is relative in sense from the nature of hierarchy of a system. For example, in the hierarchical system of social organization, it includes the effect of the international system, the national system, the enterprise system, the family system, etc. Meanwhile, the enterprise system and the national system can also become an environment of the family system.