Short receipt of goods after bill was created

Short receipt of goods after bill was created

Hi Guys

This is my first query on Zoho. I am a big fan of Zoho inventory and Zoho books. But i feel it is not perfect enough and does not handle some basic but critical operations. E.g excess delivery of goods. Anyways here is my question and i need your help:

  1. We have created a PO in the system for 500 units
  2. The accounts department received the bill before the goods were delivered and counted
  3. The accountant converted the PO into a bill
  4. When the goods were received they were short of 10 units. 
  5. The warehouse manager has no option to choose how many units he actually received as the PO has already been converted into a bill and he is obliged to receive the qty mentioned in the PO and there is no field to manually enter the units actually recd. 
This is not the case if you receive the goods first and then convert the receipt into a bill. 

Thanks