This paper systematizes the Loosely Coupled System (LCS) Theory and considers its "set" conditions using the General System Theory. In particular, Karl E. Weick, one of the most famous LCS theorists, has been considered here. He has significantly influenced organizational theory. First, the paper defines loose coupling and LCS: loose coupling refers to simple ties between systems, whereas LCS refers to some loose couplings between the subordinate systems and the "set" as a whole. Second, the paper reveals the relation between the function of loose coupling and the two main functions of LCS, "adaptability" and "local adaptation." Although LCS is a source of adaptability, it can only do so when the subordinate systems having sensitive sensory functions cope with each environmental change. Third, LCS can be further differentiated to produce generalists and is integrated with "presumption of logic" and "metamanagement." Furthermore, these integrations are related to "hierarchizing." A university has been considered as a specific example of LCS here.