How and where to add the excess quantity % in VA01 screen

Hi Genius..

My query is : In SAP-AFS, I have a customer order for 100 pcs for the particular size, if I want to give an excess quantity for the particular size. How and where to add the excess quantity in VA01 screen.

For example:

S – 100 + 10 (Excess qty to avoid mistakes and damages to reach 100 pcs at last)

M – 200 + 10 (Excess qty to avoid mistakes and damages to reach 200 pcs at last)

L – 300 + 10(Excess qty to avoid mistakes and damages to reach 300 pcs at last)

XL – 400 + 10(Excess qty to avoid mistakes and damages to reach 400 pcs at last)

Thanks in advance

Regds

Prabakaran