Dear Kgs Venkatesan

This is the principle of Divide and Conquer, largely applyed on programming/systems development.

Please, read this: https://www.cs.kent.ac.uk/people/staff/djb/ProblemSolving/doc1.n-S-3.html

Regards.

Kgs Venkatesan

Its contextual decision to select appropriate design approach and techniques.

In Laymen words, Modular design approach may help you to break down and come out with next level question, where to apply what?

Even in many cases, modularity has some disadvantages as well, i would suggest first analysis your problems and break down to possible

decoupled modules then think about next level techniques.

You can use tree decisions to distribute into small parts