System: The word system was coined from the Greek word “Systema” the meaning of which is the interactive collection of various processes of achieving the common goal. The meaning in short is a defined method of performing any work. Thus system is the collection of various operations and components for achieving some common objectives which are interrelated.

a) Definition: The system composed of a hierarchy of subsystem i.e. each system may be made up of subsystem and in turn each subsystem can itself be composed of subsystem, and thus every system except the largest has a supra system (environment) and every system except the smallest has subsystem.

According to Martin a system is simply an assemblage or combination of things or parts forming a complex whole.

According to Richard Johnson, “a system is an organized complex whole”.

According to Ludwing, “a system is a set of units with relationship among them”.

According to Johnson, Kast and Rosenzwig, “a system is an organized or complex whole, an assemblage or combination of things or parts forming a complex unitary whole”.

According to Hickey, “a system is an assemblage of object united by some form of regular interaction or interdependence which collectively contributes towards an important and complex function”.

So by considering all the above definition, a system could be defined as an entity, conceptual or physical which consists of interrelated, interacting or interdependent parts. In functional element, it may be regarded separately from each other but is not independent of the environment in which it exists.

b) Characteristic of a System: Any system has the following characteristics

i) Simple

ii) Functional

iii) Systematic

iv) Resourceful

v) Flexibility

vi) Adaptability

vii) Dependability

viii) Acceptability

c) Elements of a System: The main elements of a system are-

i) Input: The input devices bring anything to the main memory of a system.

ii) Storage: It is the work space area within the system where data and instruction are stored.

iii) Processing Unit: Major calculation and comparison are made within the processing unit.

iv) Output: Output presents the information in a form which is intelligible to the user.

v) Boundaries and Interface: A system is defined by its boundaries –limit that identifies its components and process. Every system should have boundaries which are distinguishable from the environment (Supra system) in which it resides. The points where inputs pass into system and output pass into environment are called interfaces. In other words, interfaces are those boundaries where the system interacts with environment.

vi) Environment: Every system has an environment surrounding it. The environment is the supra system within which an organization or system operates. Anything outside the boundary of a system constitutes its environment.

d) Classification of a System: System may be classified in many different ways, some of them are-

i) Natural System: The systems which are beyond the control of human are natural system. Example: Physical and biological system.

ii) Man Made System: The system which is under the control of human beings. Example: Social, economic, political, library system, etc.

            The distinction between the above two are blurred these days because nothing is left behind the control or effect of human beings.

            The system can also be classified as follows

i) Open System: The system that exchange material energies or information with their environment.

ii) Closed System: The system where there is no import and export of energies in any of its forms such as information, heat, physical material, etc.

iii) Adaptive System: The adaptive system responds to the environment changes. They react to the environmental changes in a way that is desirable, considering the purpose.

iv) Non Adaptive System: The system which does not respond to the environmental changes.

v) Physical System: It includes human digestive system and the blood circulatory system.

vi) Abstract System: It includes the purchasing system and shipping system of an enterprise.