The negative inventory clearing account doesn’t function as intended.
If this account was functioning as intended then the cost of goods sold would be affected and this account would not have anything left in it.
I understand you shouldn’t have a ‘negative inventory’ however: if you haven’t got that inventory then the correct handling is to have negative inventory and not have any costs associated with the invoice. Why? Simple. You haven’t incurred a cost at the time of creating the invoice, you incur the cost at the time of production. Therefore the production order is what controls the cost associated with the invoice if the inventory item is created from other materials. The invoices already handle the cost of inventory when the item is a direct to customer inventory item you buy (eg: buy a book, sell that exact book). But if you create the book then the cost should be associated only with the book on the day the production is completed.
I have many issues with incorrect values when the amount on the invoice matches the amount created in my production order and your ‘negative inventory clearing account shows a value’ as this is supposed to be an exact value, an average doesn’t work, especially when the production orders should be linking properly to the invoices.
Let me ask a simple question: why can’t I associate a production order directly to an invoice? This is the one thing holding back your system from functioning the way you want it and it would give 100% accurate cost of goods if the value of the production order was linked just like a quote or a delivery note. Since I print photos and my customers order them framed and laminated, it requires 2 production orders to be able to produce this result. If I could link them I wouldn’t have to use the reference as the invoice number as this requires 2 production orders to complete 1 invoice. I have to use numbers like 268-1 and 286-2 so I know what invoice they go to. If I could link them directly then the reference number wouldn’t matter and I could marry them up using the invoice number instead.