sales of product in selling and administrative expense uniformly over the remaining guarantee period. 

Property, Plant and Equipment and Definite- Lived Assets 

Property, plant and equipment, including buildings, equipment, and computer hardware and software are recorded at cost (including, in some cases, the cost of internal labor) and are depreciated over the estimated useful life. Changes in circumstances (such as technological advances or changes to our business operations) can result in differences between the actual and estimated useful lives. In those cases where we determine that the useful life of a long-lived asset should be shortened, we increase depreciation expense over the remaining useful life to depreciate the asset’s net book value to its salvage value. 

We review the carrying value of long-lived assets or asset groups to be used in operations whenever events or changes in circumstances indicate that the carrying amount of the assets might not be recoverable. Factors that would necessitate an impairment assessment include a significant adverse change in the extent or manner in which an asset is used, a significant adverse change in legal factors or the business climate that could affect the value of the asset, or a significant decline in the observable market value of an asset, among others. If such facts indicate a potential impairment, we would assess the recoverability of an asset group by determining if the carrying value of the asset group exceeds the sum of the projected undiscounted cash flows expected to result from the use and eventual disposition of the assets over the remaining economic life of the primary asset in the asset group. If the recoverability test indicates that the carrying value of the asset group is not recoverable, we will estimate the fair value of the asset group using appropriate valuation methodologies that would typically include an estimate of discounted cash flows. Any impairment would be measured as the difference between the asset group’s carrying amount and its estimated fair value. 

Goodwill and Indefinite-Lived Intangible Assets 

We perform annual impairment tests on goodwill and intangible assets with indefinite lives in the fourth quarter of each fiscal year, or when events occur or circumstances change that would, more likely than not, reduce the fair value of a reporting unit or an intangible asset with an indefinite life below its carrying value. Events or changes in circumstances that may trigger interim impairment reviews include significant changes in business climate, operating results, planned investments in the reporting unit, planned divestitures or an expectation that the carrying amount may not be recoverable, among other factors. We may first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events and circumstances, we determine that it is more likely than not that the fair value of the reporting unit is greater than its carrying amount, the two-step impairment test is unnecessary. The two-step impairment test requires us to estimate