Why we use the adjustment orders in inventory systems.

When we use an inventory system, we mean that we record all operations with the goods by our warehouse. But it is not always true. Sometimes we make mistakes, sometimes we do not receive all ordered goods. Sometimes the goods are stolen or spoiled.Usually we find out the problem after physical counting of the goods in our wrehouses. What should we do in this case? We have to create a new adjustment order and enter in it all problem items. The inventory system will recalculate quantity on hand. And we will have a document showing the gap in the stock. Adjusting is the same transaction as receiving or shipping.Or rather it is sending of goods in nowhere.