Hi Jeevitha,
Thank you so much.
Regarding Value Mapping. I request you to go through the weblink below:
http://help.sap.com/saphelp_nw73ehp1/helpdata/en/2a/107e72fffc4b7e96730d2903b17a15/frameset.htm
In this weblink it is clearly mentioned about Value Mapping. If you required more details, let me know. Thanks.
Regards,
Hari Suseelan