Property, Plant and Equipment

12 Months Ended

Jan. 29, 2017

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, Plant and Equipment

The following is a summary of property and equipment, at cost less accumulated depreciation:

(in thousands)	January 29, 2017			January 31, 2016
Property	$	11,314		$	8,888
Buildings	30,294			18,749
Leasehold improvements	9,566			10,182
Machinery and equipment	150,276			141,357
Enterprise resource planning systems	28,166			28,166
Furniture and office equipment	35,025			35,907
Construction in progress	5,505			1,539
Property, plant and equipment, gross	270,146			244,788
Less accumulated depreciation and amortization	(161,236		)	(143,782		)
Property, plant and equipment, net	$	108,910		$	101,006

As of January 29, 2017 and January 31, 2016, construction in progress consists primarily of machinery and equipment awaiting completion of installation and being placed in service.

During the fiscal year ended January 29, 2017 and January 31, 2016, the Company did not record significant impairment charges.

During the fiscal year ended January 25, 2015, the Company recorded impairment charges against certain property, plant and equipment assets as a result of its strategic decision to reduce its investment in the defense and microwave communications infrastructure market and further reduce its investment in the optical long-haul markets. These impairment charges relate primarily to limited sales volumes through the remaining life of the assets. In determining the amount of impairment, the Company used a sales comparison method and cost approach to estimate the fair value of property, plant and equipment, and an income approach to estimate the fair value of intangible assets. The Company concluded that the Systems Innovation Group is the asset group for impairment testing purposes. The categorization and classification of these charges, recorded in fiscal year 2015, are summarized below:

(in thousands)	Machinery and equipment		Furniture and office equipment		Leasehold improvements		Total
Cost of sales	$	2,799	$	10	$	1	$	2,810
Product development and engineering	3,477		33		—		3,510
Selling, general and administrative expenses	5		—		1		6
Total impairment charge	$	6,281	$	43	$	2	$	6,326

Depreciation expense was $21.7 million, $23.2 million, and $21.1 million in fiscal years 2017, 2016, and 2015, respectively.