Current Liabilities

Deferred Services Income

A portion of our revenue is generated from service contracts. Payments from certain of these service contracts are collected in advance. As such, revenues from these service contracts are deferred and recognized ratably over the contract period for time-based service contracts, or as service hours are delivered for contracts based on a purchased quantity of hours.

Changes in our deferred service revenue were as follows:



	Three Months Ended
(In thousands)	April 1, 2017			April 2, 2016
Balance, beginning of the period	$	3,842		$	4,011
Additions	1,073			1,179
Revenue recognized	(850		)	(1,016		)
Balance, end of the period	$	4,065		$	4,174
Balance sheets classification
Deferred service income-short term	$	3,170		$	4,174
Deferred service income-long term	895			—
Balance, end of the period	$	4,065		$	4,174

Other current liabilities

Other current liabilities consisted of the following:



(In thousands)	April 1, 2017		December 31, 2016
Salaries and benefits	$	9,319	$	11,494
Warranty accrual	2,126		1,884
Advanced billings	535		583
Capital lease, current portion	289		504
Other	1,538		3,563
Balance, end of the period	$	13,807	$	18,028

Warranty Accrual

We generally warrant our new and refurbished products for material and labor to repair the product for periods of twelve months and three months, respectively, from the date of system acceptance. Accordingly, an accrual for the estimated cost of the warranty is recorded at the time the product is shipped. Extended warranty terms, if granted, result in deferral of revenue equating to our standard pricing for similar service contracts. Recognition of the related warranty cost is deferred until product revenue is recognized. Factors that affect our warranty liability include the number of installed units, historical and anticipated rates of warranty claims and cost per claim. We periodically assess the adequacy of our recorded warranty liabilities and adjust the amounts as necessary. We believe our warranty accrual as of April 1, 2017 is sufficient to satisfy our outstanding obligations as of that date.

Changes in our warranty accrual were as follows:



	Three Months Ended
(In thousands)	April 1, 2017			April 2, 2016
Balance, beginning of the period	$	1,884		$	1,586
Liabilities accrued for warranties issued	813			653
Warranty claims paid and utilized	(558		)	(548		)
Changes in accrued warranty liabilities	(13		)	(21		)
Balance, end of the period	$	2,126		$	1,670