Reducing the inventory value to be equal to the net book value to get, considering each type of product, but in some circumstances may be based on groups of items that have similar characteristics or that are tied together.
Reduction of inventories to net realizable value received. Consider the value of each product, but in some situations. In the case of products that are similar or related.
Reduction of inventory to equal the net realizable value. Consider from each product type, but in some situations. May consider the items with similar or with associated.