Inventories are usually written down to net realisable value on an item by item basis. In
some circumstances, however, it may be appropriate to group similar or related items.
This may be the case with items of inventory relating to the same product line that
have similar purposes or end uses, are produced and marketed in the same
geographical area, and cannot be practicably evaluated separately from other items in
that product line. It is not appropriate to write inventories down based on a
classification of inventory, for example, finished goods, or all the inventories in a
particular industry or geographical segment. Service providers generally accumulate
costs in respect of each service for which a separate selling price will be charged.
Therefore, each such service is treated as a separate item.