The Complexity Index, C, is used to indicate
inherent complexity of a problem, or class of problems. The
Complexity Index is defined in terms of:

V
= The number of independent Variables needed to describe the
state of the system.

P = The number of independent
Parameters needed to distinguish the system from other systems in
the same class.

L = The number of control feedback
Loops both within the system and connecting the system to
the surroundings.

The upper and lower values of C
are defined as V + P + L >
C >V . P . L,
noting that when L
= 0, or V and P both have low values,
C is taken to be V + P + L.
For a particular system, the location of the value of
C between these upper and lower bounds will depend on
the degree of ‘connectedness’ within the structure of the system
and between the system and its surroundings (Kline, 1995: 49-51).