I am not able to find the answer of my question hence writing to everybody.
I am so curious to find out the best approach to maintain the script. I want to manage my scripts, library files and object repository in such a way that in long run it will not take much time to make the changes or update the scripts.
Also if you are using shared object repository then don't forget to take bakup of OR. yuo should know that once the OR size exceeds 2 MB it slows down Creating/Editing and running scripts considerably.