III) Subsystem :- a subsystem is part of a large system.
Each system is
composed of subsystems, which in turn are made up of other subsystems,
each subsystem being delineated by its boundaries. The interconnections and
interactions between the subsystems are termed interfaces.
Supra system :- a supra system refers to the entity formed by a system
and other equivalent subsystems with which it interacts. For example an
organization may be subdivide into numerous functional areas such as
marketing finance etc. each of these functional areas can be viewed as a
subsystem of a larger system. For example marketing may be viewed as a
system that consists of elements such as market research, advertising etc
collectively these elements in the marketing area may be viewed as making
up the marketing supra system.