Fixed assets consisted of the following (in thousands):
 Estimated Useful Life in YearsMarch 31,
 20252024
Furniture and fixtures
3-7
$9,586 $8,580 
Computer equipment and internal use software
2-3
191,098 188,799 
Leasehold improvements (1)
up to 12
52,175 52,121 
Demonstration and spare part units
2-3
19,805 20,153 
272,664 269,653 
Less – accumulated depreciation(251,135)(243,166)
$21,529 $26,487 
(1) Leasehold improvements are depreciated over the shorter of the lease term or anticipated useful life of the improvement.

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.