Those who want to avoid negative stock scenarios could install the widely approved OCA module: https://odoo-community.org/shop/stock-disallow-negative-2467#attr=19307

Negative on hand inventories do not exist in real life but it's a great feature. Your use case is not 100% right. If you have 5 apples in your inventory and sell 10, before having done the delivery, you get: - forecasted quantities: -5 - on hand quantities: +5 It's of course impossible that, in the future, you get "-5" apple in your inventory. But it's a great information since it tells you that if you do nothing, you will be 5 apples short according to what you promised to your customers. In real life, if your inventory is correct, you will deliver 5 apples to your customer and keep the others 5 in a backorder. But if, in real life, you force the system and deliver 10, Odoo lets you do it instead of blocking the delivery order operation. (which is correct because if you really delivered 10 apples, your delivery order must be 10 apples, even if Odoo think there is only 5 on hand) In that case, the on hand inventory becomes "-5". Even if it's not possible in the real life, it's a good information because it tells you that you made a mistake when recording incoming/ship ping operations. The most probable reason is that you forgot to record an incoming shipment. When you will record the missing incoming shipment (or do an inventory for this product), the on hand inventory will become positive again. Not that by doing so, Odoo ensure that: "on hand inventory" is always equal to "incoming - outgoing shipments", like in the real life.

Note that putting 0 instead of "-5" would be erroneous as you break this equation. And, when you will record the missing incoming shipment, your inventory will be completely wrong.

I have to agree with you, but the current stock does not work like that. The reason for this being that both "on-hand" as well as "forecasted" values are calculated, not set numbers. So basically, OpenERP is will calculate each time something relevant happens to the stock location and/or product (for example selling it, or moving it from one location to the other). Up front, OpenERP only knows at one specific moment if the move is going to take the stock to anything less then zero, thus giving you a warning ("You are about to sell 10 but you only have 5, are you sure?"). Should you ignore this warning then OpenERP assumes the current stock is somehow manipulated outside of OpenERP ( you bought 20 apples from the guy down the road and put them in your inventory) and still allows you to make that sale.

The folks over at Odoo already promised to work on stock in the new version, so I wonder if this issue will remain when Odoo 8 is finally stable.