
	As of December 31,
	2023		2022
Production and service materials	$	719.0	$	479.6
Finished goods	299.0		163.3
Total inventory	$	1,018.0	$	642.9

Reported as:
Inventory	$	952.4	$	619.4
Other long-term assets (1)	65.6		23.5
Total inventory	$	1,018.0	$	642.9

(1) Long-term inventory balance classified as other long-term assets in the Company's Consolidated Balance Sheets consists of last time buy component inventory to be consumed beyond the Company's normal operating cycle.


	As of December 31,
	2023		2022
Contract manufacturer deposits	$	316.4	$	434.7
Prepaid expenses	140.9		104.3
Other current assets	134.2		141.0
Total prepaid expenses and other current assets	$	591.5	$	680.0


	As of December 31,
	2023		2022
Computers and equipment	$	990.0	$	940.0
Software	221.3		220.3
Leasehold improvements	185.9		189.2
Furniture and fixtures	45.3		45.4
Building and building improvements	292.8		271.9
Land and land improvements	243.6		243.6
Construction-in-process	4.1		12.1
Property and equipment, gross	1,983.0		1,922.5
Accumulated depreciation	(1,293.1)		(1,255.7)
Property and equipment, net	$	689.9	$	666.8

Depreciation expense was $123.5 million, $137.7 million, and $151.0 million in 2023, 2022, and 2021, respectively.


	As of December 31,
	2023		2022
Beginning balance	$	29.5	$	33.0
Provisions made during the period, net	31.9		30.1

Actual costs incurred during the period	(32.0)		(33.6)

Ending balance	$	29.4	$	29.5

Details of the Company's deferred revenue, as reported in the Consolidated Balance Sheets, were as follows (in millions):


	As of December 31,
	2023		2022
Deferred product revenue, net	$	92.1	$	108.8
Deferred service revenue, net	1,932.8		1,554.3
Total	$	2,024.9	$	1,663.1
Reported as:
Current	$	1,130.0	$	1,020.5
Long-term	894.9		642.6
Total	$	2,024.9	$	1,663.1

See Note 11, Segments, for disaggregated revenue by customer solution, customer vertical, and geographic region.

Product revenue of $48.3 million included in deferred revenue at January 1, 2023 was recognized during the year ended December 31, 2023. Service revenue of $907.3 million included in deferred revenue at January 1, 2023 was recognized during the year ended December 31, 2023.

Remaining Performance Obligations (RPO) are comprised mainly of deferred product and service revenue, and to a lesser extent, unbilled service revenue from non-cancellable contracts for which the Company has not invoiced and has an obligation to perform, and for which revenue has not yet been recognized in the financial statements.

The following table summarizes the breakdown of RPO(1) as of December 31, 2023 and when the Company expects to recognize the amounts as revenue (in millions):


	Revenue Recognition Expected by Period
	Total		Less than 1 year		1-3 years		More than 3 years
Product	$	92.9	$	77.3	$	12.9	$	2.7
Service	1,943.9		1,059.2		666.2		218.5
Total	$	2,036.8	$	1,136.5	$	679.1	$	221.2

(1) The Company's RPO does not include backlog. Backlog consists of purchase orders for product expected to be shipped to the Company's distributors, resellers, or end-customers within the next twelve months. The following amounts are not included in the Company's backlog: (1) deferred revenue, (2) unbilled contract revenue, (3) all service obligations, including software as a service (SaaS), and (4) certain future revenue adjustments for items such as sales return reserves and early payment discounts.

Deferred contract costs were $41.9 million and $28.2 million as of December 31, 2023 and 2022, respectively. During the years ended December 31, 2023 and 2022, amortization expense for the deferred contract cost were $42.4 million and $35.0 million, respectively, and there were no material impairment charges recognized.


	Years Ended December 31,
	2023		2022		2021
Interest income	$	50.6	$	19.6	$	14.9
Interest expense	(80.0)		(58.6)		(50.8)
Gain (loss) on other investments, net (1) (2)	6.0		(11.6)		4.9
Other	(0.4)		1.6		1.5
Other expense, net	$	(23.8)	$	(49.0)	$	(29.5)

(1) Other investments represent fixed income securities and equity investments with readily determinable fair value.