Other Balance Sheet Information

The following is a summary of accounts receivable at March 31, 2015 and September 30, 2014 (in thousands):



	March 31, 2015			September 30, 2014
Accounts receivable	$	96,066		$	81,270
Less allowance for doubtful accounts	(1,261		)	(1,031		)
Less allowance for sales returns	(126		)	(133		)
	$	94,679		$	80,106

The following is a summary of inventories at March 31, 2015 and September 30, 2014, excluding amounts related to discontinued operations (in thousands):



	March 31, 2015		September 30, 2014
Inventories
Raw materials and purchased parts	$	55,456	$	57,250
Work-in-process	19,600		20,068
Finished goods	15,502		16,249
	$	90,558	$	93,567

Reserves for excess and obsolete inventory were $24.9 million and $26.0 million, excluding amounts related to discontinued operations, at March 31, 2015 and September 30, 2014, respectively.

The Company provides for the estimated cost of product warranties, primarily from historical information, at the time product revenue is recognized and retrofit accruals at the time retrofit programs are established. The Company’s warranty obligation is affected by product failure rates, utilization levels, material usage, service delivery costs incurred in correcting a product failure, and supplier warranties on parts delivered to the Company.

Product warranty and retrofit activity on a gross basis for the three and six months ended March 31, 2015 and 2014, excluding amounts related to discontinued operations, is as follows (in thousands):



Activity - Three months ended March 31, 2015
Balance at December 31, 2014		Adjustments for Acquisitions and Divestitures		Accruals		Costs Incurred			Balance at March 31, 2015
$	6,255	$	—	$	2,428	$	(2,480	)	$	6,203



Activity - Three months ended March 31, 2014
Balance at December 31, 2013		Adjustments for Acquisitions and Divestitures		Accruals		Costs Incurred			Balance at March 31, 2014
$	6,762	$	—	$	2,275	$	(2,718	)	$	6,319



Activity - Six months ended March 31, 2015
Balance at September 30, 2014		Adjustments for Acquisitions and Divestitures		Accruals		Costs Incurred			Balance at March 31, 2015
$	6,499	$	81	$	5,145	$	(5,522	)	$	6,203



Activity - Six months ended March 31, 2014
Balance at September 30, 2013		Adjustments for Acquisitions and Divestitures		Accruals		Costs Incurred			Balance at March 31, 2014
$	7,260	$	—	$	4,150	$	(5,091	)	$	6,319