One of my Client wanted "During MIGO (GR with reference to PO), the default Quantity should be Zero; Instead of Open PO Quantity".
So I searched SDN but I could not get an answer.
Hence thought of posting this document, so that it would be useful to someone with the same requirement.
For this we need to use BADI - MB_MIGO_BADI
Create a BADI as shown below

Double Click on the Class and in the Attributes, create as shown below.

ZMM_MIGO_BADI_T is a table type with the following structure.

Now write the following code in the BADI Methods.

Output Before Implementing BADI

Output After Implementing BADI
