Notice the explicit use of multiple cost objects in the room-service example. In
determining that price, management treats an individual unit of each item as the cost
object. In determining the delivery charge to be added to each order, the order is treated
as the cost object. This is a reasonable pattern of pricing because the cost of a delivery is
not traceable to an item, but to the delivery of an order. Do not be confused by the trivial
case in which an order consists of a single item. The delivery cost of a single-item order
is traceable to the item only because the item and the order are identical in that instance.
In general, it is the order, of any size, that causes the delivery cost to be incurred.