Computer Sciene of Udayana State University

February 19, 2009

Methods of System’s Study

Filed under: Computer Science — ignaga @ 11:48 AM

There are several important system’s concepts that help to study a system and understand
its functioning:
• Decomposition
• Modularity
• Coupling
• Cohesion

• Decomposition is the process of breaking down a system into its smaller components.
These components may themselves be systems (subsystems) and can be broken down into
their components as well. How does decomposition aid understanding of a system? It results in smaller and less complex pieces that are easier to understand than larger, complicated pieces

• Modularity is a direct result of decomposition. It refers to dividing a system into chunks
or modules of a relatively uniform size. Modules can represent a system simply, making it
easier to redesign and rebuild. For instance, a portable CD player, as a system, accepts CDs
and settings of volume and tone as inputs and produces music as output. It includes the
separate systems as its subsystems: 1) read the digital signals from CDs; 2) amplify the
signals; 3) turn the signals into sound waves; and 4) control the volume and tone of the

figure 1.2

figure 1.2

• Coupling means that subsystems are dependent on each other. But they should be as
independent as possible. If one subsystem fails and other subsystems are highly dependent
on it, the others will either fail themselves or have problems functioning.

• Cohesion is the extend to which a subsystem performs a single function. In the CD player
example, signal reading is a single function.



  1. Your summary of my lecture is really good. It contains all materials which I taught last week and even you manage to add some new information such as above. You also manage to be the first to post. I just hope you wrote all of the materials by your own. Well done!

    Comment by Agus Sanjaya — February 20, 2009 @ 12:55 AM | Reply

    • thanks sir for the comment, i am sorry that i very late to reply your comment.

      Comment by ignaga — August 31, 2010 @ 11:58 AM | Reply

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