SAP Research Sticker--Invoice Check tip Moving average price is negative

Recently, due to post-intensive invoice check when the moving average value of negative results in the posting failed, the procurement manager is to shoot the table, but also fell cup. The finance Manager arranges a thorough inventory to find out the cause of the problem.
Oh, no clue ... Test machine Simulation Business Bar
Process: Contract (off-system)-Purchase order (me23n)-Purchase order Receipt (MB01)-Invoice check (MIRO)
1) voucher flow for normal business:
1, Borrow: raw materials 100 order price and quantity 10 Yuan * 10, invoice unit price and quantity 10 Yuan * 10 only
Loan: 100 of the provisional estimate payable
2. Loan: 100 of the provisional estimates payable
Borrowing: Input Tax 17
Credit: 117 of the Bill payable
2) actual Business voucher Flow 1: Order unit Price and quantity 10 Yuan * 10, invoice unit price and quantity 5 Yuan * 10 only, invoice check time inventory quantity 10 only
1. Borrowing: Raw materials 100
Loan: 100 of the provisional estimate payable
2. Loan: 100 of the provisional estimates payable
Borrowing: Input Tax 8.5
Credit: 58.5 of the bill payable
Credit: Raw Materials 50
3) Actual Business Voucher Flow 2: Order unit Price and quantity 10 Yuan * 10, invoice unit price and quantity 5 Yuan * 10 only, invoice check time inventory quantity 6 only
1. Borrowing: Raw materials 100
Loan: 100 of the provisional estimate payable
2. Loan: 100 of the provisional estimates payable
Borrowing: Input Tax 8.5
Credit: 58.5 of the bill payable
Credit: Raw Materials 30
Credit: Material Cost Variance 20
4) Actual Business voucher Flow 3: Order unit Price and quantity 10 Yuan * 10, invoice unit price and quantity 15 Yuan * 10 only, invoice check time inventory quantity 10 only
1. Borrowing: Raw materials 100
Loan: 100 of the provisional estimate payable
2. Loan: 100 of the provisional estimates payable
Borrowing: Input tax 25.5
Borrowing: Raw materials 50
Credit: 175.5 of the bill payable
5) Actual Business voucher Flow 4: Order unit Price and quantity 10 Yuan * 10, invoice unit price and quantity 15 Yuan * 10 only, invoice check time inventory quantity 6 only
1. Borrowing: Raw materials 100
Loan: 100 of the provisional estimate payable
2. Loan: 100 of the provisional estimates payable
Borrowing: Input tax 25.5
Borrowing: Raw materials 30
Borrowing: Material Cost Variance 20
Credit: 175.5 of the bill payable

Through the simulation of 5 kinds of cases, we can generally see the invoice check logic of SAP. The price of the invoice and the price difference at the time of receipt, apportioned between the inventory quantity and the invoice quantity. Invoice Quantity < Inventory quantity, update the inventory value all. Invoice Quantity > Inventory quantity, update the stock value for the difference in the Inventory section, update the material price variance for discrepancies in the Invoice part > Inventory section.

Here's the problem.

For the actual business 1, 2, that is: Invoice Check Unit price < purchase order Unit price, in the invoice check may have the inventory value is not enough to buckle, in such cases, there will be "moving average price is not negative" error.
Carding the company's processes, contracts, orders when the price is not controlled, invoice check the price of strict control, for this process, may appear the order price and invoice price is too large.

Big uncle's, the problem found out. The order price is your purchase department tube, invoice price is also your purchase department tube, you and my finance department roar a wool ah, oneself make out of problem, oneself play go, bye to you now ....

SAP Research Sticker--Invoice Check tip Moving average price is negative