Miller: Hierarchy, system, sub-system, component

Continuing this post. From the basic concepts of Living Systems by James Grier Miller:

"It would be convenient for theorists if the hierarchical levels of living systems fitted neatly into each other like Chinese boxes. The facts are more complicated, as my discussion of subsystems and components indicates" (Sec. 8).

"In every system it is possible to identify one sort of unit, each of which carries out a distinct and separate process, and another sort of unit, each of which is a discrete, separate structure. The totality of all the structures in a system which carry out a particular process is a subsystem. A subsystem, thus, is identified by the process it carries out. It exists in one or more identifiable structural units of the system. These specific, local, distinguishable structural units are called components or members or parts. [...] The concept of component process is related to the concept of role used in social science. [...] A role is more than simple 'social position,' a position in some social space which is 'occupied.' It involves interaction, adjustments between the component and the system. It is a multiple concept, referring to the demands upon the component by the system, to the internal adjustment processes of the component, and to how the component functions in meeting the system's requirements. The adjustments it makes are frequently compromises between the requirements of the component and the requirements of the system."

"In defining 'system' I indicated that the state of its units is constrained by, conditioned by, or dependent upon the state of other units. That is, the units are coupled. Some systems and components are also constrained by their suprasystems and subsystems. The form of allocation of process to structure determines the nature of the constraint or dependency in any given system. Living systems are so organized that each subsystem and component has some autonomy and some subordination or constraint from lower-level systems, other systems at the same level, and higher-level systems. Conflicts among them are resolved by adjustment processes" (Sec. 11).