Question { Accenture, 18246 }

If I have one PO with me & I made GR with partial Qty &
after that I want to block PO for one month means user
shouldn't make GR against this PO & after one system should
allow to make GR. In this case where I need to do changes?

Answer

Check "Delivery Completed" Indicator In this case along with putting tick on "Delivery Completed" Indicator, you should also block the line item in ME22N for further GRN.
 
Also one more way you can adopt is of changing the quantity in the PO, In your case changing to 10, but by doing this in future you will not be able to analyze what went wrong with this PO.