Refactoring a software application

Refactoring : a change made to the internal structure of software to make it easier to understand and cheaper to modify without changing its observable behavior.

The rhythm of refactoring: test, small change, test,small change, test, small change ...

Why you need to refactor :

1. Improves the Design of Software :Any software decays over a period of time as requirements changes ,Refactoring helps in  preventing the software decay  
2. Makes Software Easier to Understand:
3. Helps You Find Bugs
4. Helps You Program Faster

When you need to Refactor?:

1. Before adding new function/capability/feature
2. Before fixing a bug
3. While reviewing code
4. To understand legacy application

When you need not refactor ?:

1. The application is not working
2. The application is full of bugs
3. The code base is not stabilized