I AM WORKING AS A CAD ENGINEER I HAVE MADE MORE FABRICATION DRAWING FOR NEW PLANT PROJECT NOW THE PROJECT IS COMPLETED. SO I AM PLANNING TO SEGREGATE ALL FABRICATION DRAWING AND GIVING DRAWING NUMBERING ALSO COULD YOU TELL ME HOW TO GIVE DRAWING NUMBERING PROPERLY WITH EXAMPLE. 

Then I guess you can create your own methodology for numbering your drawings.  One company I know precedes the drawing number with a letter denoting the paper size.  Example:

D-12335

The "12335" may just be a consecutive number assigned as a project comes in.  Drawings assigned this master number will then get a sequential dash-number for each sheet.  Example:

D-12335-1 (for sheet 1), D-12335-2 (for sheet 2), D-12335-3, etc.

Now if there happens to be a smaller sheet size used for the next drawing in the sequence it might get numbered thusly...

C-12335-4

The "D" and "C" size designations obviously reference drawings done to an imperial scale.  You would substitute metric equivalents for the sheet size.  Do you understand me?

The last company I worked for numbered their drawings with the year followed by a consecutive number.  So, for example, the first job for the year 2017 would be numbered....

2017.001

Sheet numbers would start out as 2017.001.01, 2017.001.02, 2017.001.03, etc.

If you don't like either one of these ideas come up with one of your own.