Inventory Valuation
Inventories are valued at the lower of cost or net realizable value. Product- related inventories are maintained on the first-in, first-out method. The cost of spare part inventories is maintained using the average-cost method.
Property, Plant and Equipment
Property, plant and equipment is recorded at cost reduced by accumulated depreciation. Depreciation expense is recognized over the assets’ estimated useful lives using the straight-line method. Machinery and equipment includes office furniture and fixtures (15-year life), computer equipment and capitalized software (3- to 5-year lives) and manufacturing equipment (3- to 20-year lives). Buildings are depreciated over an estimated useful life of 40 years. Estimated useful lives are periodically reviewed and, when appropriate, changes are made prospectively. When certain events or changes in operating conditions occur, asset lives may be adjusted and an impairment assessment may be performed on the recoverability of the carrying amounts.