System complexity - Boulding taxonomy 
To obtain an insight into the nature of the system with which the operations manager is dealing, consider the economist Kenneth Boulding's Taxonomy (shown in the table below), in which he classified systems into nine levels, of increasing complexity: 
Boulding's taxonomy 
1.  Static (frameworks) 
 Maps, chemical symbols, organisation charts. 
2.  Simple dynamic (clockworks) 
 Predetermined motions. Levers, pulleys, theoretical structure of physics. 
3.  Cybernetic (thermostat) 
 Self-regulation, involving communication and integration of information.
Watts governor, numerically controlled machine tools. 
4.  Self-maintaining (cell) 
 Level at which life is differentiated  from non-life. Ingestion, excretion, metabolic exchange. 
5.  Genetic (plant life) 
 Division of work among cells - cell society. Roots, leaves, seeds, etc. 
6.  Animal 
 Specialised information receptors -  eyes, ears, etc. Nervous system, information-processing, mobility, behaviour. 
7.  Man 
 Self-reflection. Memory, symbol manipulation, time-sense, speech. 
8.  Social organisations 
 The individual's role is a significant factor - a set of roles tied by their channels of communication. 
9  Transcendental 
 Abstract systems. Religions, philosophies, ideologies. 
Note that the operations systems with which we are concerned are at the second highest level of complexity in this taxonomy, ie at level 8. 
Inputs, transformation and outputs  
Levels 4 through 9 can be seen as open systems which interact with their environments. Inputs are received from the environment, are transformed by the system, and the outputs are returned to the environment.