Final answer:
An impairment loss is required if the asset's BV > the undiscounted sum of expected future cash flows.
Step-by-step explanation:
In testing for recoverability of an operational asset, an impairment loss is required if the asset's BV > the undiscounted sum of expected future cash flows.
For example, let's say a company owns a machine with a book value (BV) of $10,000. If the undiscounted sum of its expected future cash flows is only $8,000, then an impairment loss of $2,000 would be required to bring the asset's value down to its recoverable amount.