Hi Haris, I think you're getting a little confused. Design Patterns are basically a tried and tested method for solving common problems, an example of such is a singleton. Whereas OOP and procedural programming are two different methods (or styles) of programming.

As for your question, OOP should almost always be used over procedural programming. The only exception I can think of is when you're developing a small standalone script, i.e a cron job, but even then, I tend to use classes because it allows things to be organised better.