Userexit/badi for tolerance levels in production order

Hi ,

  I have a requirment where I have to set the under/over delivery tolerance limits to a fixed value based on the order quantity.I am not able to get any user exit or Badi to do the same.I am aware that this tolerance flows in from the work schedulling view in Material Master,But i need to change this in CO01/Co02.

  Can any one please help me out.

Thank you,

Suvarna.