Hello, Amar,
If you haven't reviewed the documentation for changing the default numbering scheme, you may want to start with the following topic, which introduces the concepts and links to procedures and examples:
http://www.ptc.com/cs/help/windchill_hc/wc101_hc/index.jspx?id=ObjRuleObjectNumbering&action=show
This link will take you to the topic in the instance of the Windchill Help Center running on ptc.com.
I hope this helps.
Regards,
Jane
Jane Zupfer
VP, Enterprise Products Publications
T 763.957.8299 Ejzupfer@PTC.com
PTC.com