Purchase receipt status changed to Completed issue

Hi community
We are trying to implement ERPNext in our small mentha oil trading company.
We have work flow as

  • we received ITEM(mentha OIL) from farmer .
  • They do not want to bill it on same day they wait till the market rate goes up.
  • they can bill the item in parts
  • we only can bill them as per their convenience.

All looks fine if we make purchase receipt and then make invoice from these purchase receipt.
Problem arises with the rate difference for example

  1. We received on 01/01/2019 item (mentha OIL) 100 KG at that time market rate is 100 rs/kg. We make purchase receipt for the same with purchase amount 100*100=10000.
  2. On 5/01/2019 Farmer ask us to bill only 10 kg as per market rate which is 250 rs/kg. We invoice him 10 KG *250 =2500 with option get ITEM from purchase receipt .
  3. On 10/01/2019 farmer ask to bill his 30 kg ,we invoice him for 30KG*750=7500
    Until now system works fine,but again on 15/01/2019 when former ask to bill his remaining 60 kg at the rate 500 ,we cant invoice him as when we use get Item from purchase invoice it shows no purchase receipt is pending.

On further investigation it shows purchase receipt status as Completed.
It looks like system shows only those purchase receipt whose amount is pending not the quantity is pending

**Date Item (Mentha Oil In KG) rate amount purchase receipt status**
01/01/2019 100 100 10000 To bill
05/01/2019 10 250 2500 To bill
10/01/2019 30 250 7500 Completed

We have to bill its all quantity .
Could please suggest any work around form the same.
Thanks

Hi community
Please suggest if there is any solution for the issue

Hi Community
I have found as this is an old issue which is fixed in

I can see in screenshot ,there is an option for setting “Billing percentage based on => amount” option ,I hope it also include an quantity as an option.
But I am not getting these option in my erpnext buying setting .
I am using Erpnext v11.1.13
Please help me