Inventories consist of raw materials and components, such as drivers, metal sheet and coil stock and molded parts; work in process inventories, such as frames and reflectors; and finished goods, including completed fixtures and systems, and accessories. All inventories are stated at the lower of cost or net realizable value with cost determined using the first-in, first-out (FIFO) method. Orion reduces the carrying value of its inventories for differences between the cost and estimated net realizable value, taking into consideration usage in the preceding 9 to 12 months, expected demand, and other information indicating obsolescence. Orion records, as a charge to cost of product revenue, the amount required to reduce the carrying value of inventory to net realizable value. As of March 31, 2023 and 2022, Orion's inventory balances were as follows (dollars in thousands):


	Cost		Excess and Obsolescence Reserve			Net
As of March 31, 2023
Raw materials and components	$	9,988	$	(1,094	)	$	8,894
Work in process		693		(135	)		558
Finished goods		9,313		(560	)		8,753
Total	$	19,994	$	(1,789	)	$	18,205
As of March 31, 2022
Raw materials and components	$	10,781	$	(1,140	)	$	9,641
Work in process		1,529		(267	)		1,262
Finished goods		9,593		(664	)		8,929
Total	$	21,903	$	(2,071	)	$	19,832

Costs associated with the procurement and warehousing of inventories, such as inbound freight charges and purchasing and receiving costs, are also included in cost of product revenue.