2 System and modeling concepts

2.1 What is a system?

A system is a collection of components which work together to achieve a specific goal.
These components are connected to maintain communication when they work together .
However, they have independent functionalities. Therefore, each component is another
system, named as a subsystem, which carries out tasks to achieve some objectives of the
original system.

Example 1: The Human Body

Our human body is a complex system which contains several components which acts as
subsystems. The human body consists of complex muscle, bone, respiratory, digestive and
circulatory subsystems, each providing a specific task of the overall system.
Let’s consider one such subsystem, respiratory which provides oxygen to human body. Some
components of the respiratory subsystem such as nasal passages, lungs etc. can be
considered as a subsystem. On other hand, respiratory system communicates with digestive
system as two independent components of human body.

Example 2: A School

A particular school can be considered as a component of education system in this country
(a university may be another one). At the same time, a school itself is a complete system that
includes a principal, teachers, equipment and classrooms which are its components.
Viewing complex systems as a collection of subsystems may help us handle complexity and
improve our understanding of the system.