Inventories, Net and Significant Suppliers

Inventories, net were as follows:



(In thousands)	September 30, 2018			December 31, 2017
Raw materials	$	62,835		$	43,638
Components	13,763			16,214
Work in process	8,378			1,847
Finished goods	58,195			105,178
Reserve for excess and obsolete inventory	(7,283		)	(4,288		)
Inventories, net	$	135,888		$	162,589

Reserve for Excess and Obsolete Inventory

Changes in the reserve for excess and obsolete inventory were as follows:



(In thousands)	Nine Months Ended September 30,
(In thousands)	2018			2017
Balance at beginning of period	$	4,288		$	4,205
Additions charged to costs and expenses ⁽¹⁾	5,353			1,960
Sell through ⁽²⁾	(1,240		)	(950		)
(Write-offs)/Foreign exchange effects	(1,118		)	(2,090		)
Balance at end of period	$	7,283		$	3,125


⁽¹⁾	The additions charged to costs and expenses do not include inventory directly written-off that was scrapped during production totaling $1.1 million and $0.2 million for the nine months ended September 30, 2018 and 2017, respectively. These amounts are production waste and are not included in management's reserve for excess and obsolete inventory.


⁽²⁾	These amounts represent the reduction in reserves associated with inventory items that were sold during the period.

Significant Suppliers

We purchase integrated circuits, components and finished goods from multiple sources. Purchases from the following supplier totaled more than 10% of our total inventory purchases:



	Three Months Ended September 30,
	2018				2017
	$ (thousands)		% of Total Inventory Purchases		$ (thousands)		% of Total Inventory Purchases
Texas Instruments ⁽¹⁾	$	—	—	%	$	13,115	12.4	%



	Nine Months Ended September 30,
	2018				2017
	$ (thousands)		% of Total Inventory Purchases		$ (thousands)		% of Total Inventory Purchases
Texas Instruments ⁽¹⁾	$	—	—	%	$	33,693	11.3	%


⁽¹⁾	Purchases associated with this supplier did not total more than 10% of our total inventory purchases for the indicated period.

Related Party Supplier

During the three and nine months ended September 30, 2018 and 2017, we purchased certain printed circuit board assemblies from a related party supplier. The supplier was considered a related party for financial reporting purposes because our Senior Vice President of Strategic Operations owned 40% of this supplier. In the second quarter of 2018, our Senior Vice President sold his interest in this supplier, and thus this supplier is no longer considered a related party.

Total inventory purchases made from this supplier while it was a related party were $1.1 million during the nine months ended September 30, 2018 and $1.4 million and $4.0 million during the three and nine months ended September 30, 2017, respectively.