How to deal with the Weighted Price in the purchase/sales process in the case of negative numbers?

How can I deal with the Weighted Price in the invoicing process in the case of a negative number? Delphi/Windows SDK/API
Http://www.delphi2007.net/DelphiDB/html/delphi_20061224180508129.html
According to the normal calculation method, the weighted price should be
New Weighted Price = (inventory * Weighted Price + new quantity * unit price)/(inventory + new quantity)
Sometimes, when a negative number occurs in the inventory, the new weighted value seems to be very high. Sometimes, users want to write a negative number to indicate that the new quantity is returned, this computation also seems to be a problem. How do you deal with this situation?

The price should not be negative.

New Weighted Price = (inventory * Weighted Price + absolute value of new quantity * unit price)/(inventory + absolute value of new quantity)

Does this mean that you can calculate it in this way or in actual use? I have never studied finance. When the inventory is negative, do you want to calculate the absolute value of the inventory?

The formula is normal.
New Weighted Price = (inventory * Weighted Price + new quantity * unit price)/(inventory + new quantity)
Actually
New Weighted Price = (total inventory + total new goods)/(inventory quantity + new quantity)
Under normal circumstances, the total inventory quantity should not be negative. If there is a negative number, it indicates that there is a management problem, that is, there is a shortage or damage to the inventory goods. Normal calculation can truthfully reflect this problem. As for the return of goods, it is normal that the number of new products is negative. If the inventory of goods is not enough to return the goods, the physical account cannot be processed (how can we return even more goods in stock ?), You can only wait. This is not a conflict. It is definitely wrong to take the absolute logarithm.

Supplement: financially, if there is a serious shortage or damage to inventory goods, the financial system may report the loss after checking and auditing, and re-adjust the account.

As mentioned above, do you need to determine whether the inventory meets the return quantity and whether the sales quantity cannot exceed the inventory quantity when the sales order is made? If not, will the user be prompted to stop the operation? Can I ask the user to open a ticket first and then add the import ticket?

As mentioned above, do you need to determine whether the inventory meets the return quantity and whether the sales quantity cannot exceed the inventory quantity when the sales order is made? If not, will the user be prompted to stop the operation? Can I ask the user to open a ticket first and then add the import ticket?
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In practice, what you said will not happen.
If a company purchases 100 items and finds a problem or is not applicable, it is clear that the company is looking for the supplier to return the goods. If there are only 80 items left due to use or damage, it must be able to return 80 items, the other products cannot be refunded, but can only be claimed. if the product is sold, the customer is returned, and the new product can only be increased.

Supplement: a negative number may only be caused by damage, loss, or listing of commodities. The company's finance department will solve the problem through regular or irregular inventory check.

Thank you, alimail. It seems I can use it with confidence.
New Weighted Price = (inventory * Weighted Price + new quantity * unit price)/(inventory + new quantity)
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