Can you explain why you are using the Inventory module?
It seems as if you are not keeping track of inventory but using a production order each time you sell something, is this correct?
I am strictly keeping track of inventory.
I said I am not keeping physical stock. Means I will purchase or produce items when I get an order.
I’m a bit lost here - if you do not have a physical inventory why would you want to use the Inventory module?
Could you not just use Non-inventory items?
I am just trying to understand the workflow associated with your business. In general, it is not advisable to over-complicate the way you manage the business
Yes, when a mistake happens within an inventory item then it will subsequently cause those issues however it should be easy to trace as those issues will only arise from that mistake point.
Also, your production order illustration shows that you are creating 320 of 12201201 from nothing - zero bill of materials. This implies that the product that is being recycled is being received for free.
As an example, a business could collect used engine oil for free but via a refining process could produce various by-products which are being created for accounting purposes via the production orders.
But this scenario seems to be contradicted by your comment “I will purchase”. If you are purchasing then that purchased input would be an inventory item and that inventory item would also be used as a ‘Bill of material’ input into those production orders.
That was a reply to his question, I am purchasing lot of items and also having small production unit.
thanks
Ahmed Ansar
I am using "manager’’ last three years, I want to say thanks for this very user friendly software.
I can’t use non-inventory items. In some cases i will use raw materials (depends on customers).
Ok, I’ll leave it to more experienced users to carry on from here.
I wonder has it something to do with different locations?
you said you are making production orders before selling this inventory item.
so i would recommend you to create an 
report for one month at a time.
if you think you had this issue from say June 2017, then start creating the reports from that month.
by doing this you will understand when the mismatch between Production Orders and Sales Invoices for this particular inventory item started.
I will keep some raw materials with my supplier.