Other Balance Sheet Information

The following is a summary of accounts receivable at March 31, 2013 and September 30, 2012 (in thousands):



	March 31, 2013		September 30, 2012
Accounts receivable	$	74,621	$	79,706
Less allowances	1,076		851
	$	73,545	$	78,855

The following is a summary of inventories at March 31, 2013 and September 30, 2012 (in thousands):



	March 31, 2013		September 30, 2012
Inventories
Raw materials and purchased parts	$	60,762	$	64,732
Work-in-process	20,659		20,800
Finished goods	15,180		17,453
	$	96,601	$	102,985

Reserves for excess and obsolete inventory were $25.5 million and $23.2 million at March 31, 2013 and September 30, 2012, 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, 2013 and 2012 is as follows (in thousands):

Activity — Three Months Ended March 31, 2013



Balance December 31, 2012		Adjustments for acquisitions and divestitures		Accruals		Costs incurred			Balance March 31, 2013
$	7,724	$	—	$	3,006	$	(3,005	)	$	7,725

Activity — Three Months Ended March 31, 2012



Balance December 31, 2011		Adjustments for acquisitions and divestitures		Accruals		Costs incurred			Balance March 31, 2012
$	7,293	$	—	$	3,405	$	(3,417	)	$	7,281

Activity — Six Months Ended March 31, 2013



Balance September 30, 2012		Adjustments for acquisitions and divestitures		Accruals		Costs incurred			Balance March 31, 2013
$	7,329	$	962	$	5,369	$	(5,935	)	$	7,725

Activity — Six Months Ended March 31, 2012



Balance September 30, 2011		Adjustments for acquisitions and divestitures		Accruals		Costs incurred			Balance March 31, 2012
$	7,438	$	7	$	6,923	$	(7,087	)	$	7,281