Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets, which are generally as follows:


Asset Description						Estimated Useful Life
Software						Lesser of the life of an associated license, or 4 to 7 years
Leasehold improvements						Lesser of estimated useful life or lease term
Furniture, fixtures and equipment						4 to 10 years
Computer equipment						4 to 6 years
Buildings						35 years
Vehicles						5 to 6 years

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.

Aon plc PP&E Disclosure

About PP&E Disclosures

Other Available Disclosures