6. GOODWILL AND OTHER INTANGIBLE ASSETS

As of December 27, 2019, the Company had $127.6 million of goodwill, which primarily relates to the Energy segment and the acquisitions within this segment of E3, Inc., Lime Energy, NAM, Integral Analytics and Abacus Resource Management Company (“Abacus”) and substantially all of the assets of Onsite Energy, The Weidt Group, Genesys and 360 Energy Engineers, LLC (“360 Energy”). The remaining goodwill relates to the Engineering and Consulting reporting segment and the acquisition within this segment of Economists LLC.

The changes in the carrying value of goodwill by reporting unit were as follows:


	December 28,		Additional		Additions /		December 27,
	2018		Purchase Cost		Adjustments		2019
	(in thousands)
Reporting Unit:
Energy	$	96,999	$	39,690	$	(9,791)	$	126,898
Engineering and Consulting		749						749
	$	97,748	$	39,690	$	(9,791)	$	127,647

	December 29,		Additional		Additions /		December 28,
	2017		Purchase Cost		Adjustments		2018
	(in thousands)
Reporting Unit:
Energy	$	37,435	$	59,466	$	98	$	96,999
Engineering and Consulting		749		—		—		749
	$	38,184	$	59,466	$	98	$	97,748

The Company tests its goodwill at least annually for possible impairment. The Company completes its annual testing of goodwill as of the last day of the first month of its fourth fiscal quarter each year to determine whether there is impairment. In addition to the Company’s annual test, it regularly evaluates whether events and circumstances have occurred that may indicate a potential impairment of goodwill. No impairment was recorded in any year during the three-year period ended December 27, 2019.

The gross amounts and accumulated amortization of the Company’s acquired identifiable intangible assets with finite useful lives, included in other intangible assets, net in the accompanying consolidated balance sheets, were as follows:


	December 27, 2019				December 28, 2018
	Gross		Accumulated		Gross		Accumulated		Amortization
	Amount		Amortization		Amount		Amortization		Period
									(in years)
Finite:
Backlog	$	7,134	$	3,763	$	2,514	$	2,155	1.0
Tradename		13,351		4,882		10,301		3,118	2.5	-	6.0
Non-compete agreements		2,320		1,384		1,420		1,042	4.0	-	5.0
Developed technology		14,620		3,227		12,920		944	8.0
Customer relationships		60,733		8,065		25,219		2,441	5.0	-	8.0
Total finite intangible assets	$	98,158	$	21,321	$	52,374	$	9,700
In-process research and technology (1)		—		—		1,690		—
Total intangible assets	$	98,158	$	21,321	$	54,064	$	9,700

⁽¹⁾

In-process research and technology is not amortized until put into use.

At the time of acquisition, the Company estimates the fair value of the acquired identifiable intangible assets based upon the facts and circumstances related to the particular intangible asset. Inherent in such estimates are judgments and estimates of future revenue, profitability, cash flows and appropriate discount rates for any present value calculations. The Company preliminarily estimates the value of the acquired identifiable intangible assets and then finalizes the estimated fair values during the purchase allocation period, which does not extend beyond 12 months from the date of acquisition.

The Company’s amortization expense for acquired identifiable intangible assets with finite useful lives was $11.6 million, $4.5 million and $2.4 million for the fiscal years 2019, 2018 and 2017, respectively.

Estimated amortization expense for acquired identifiable intangible assets for fiscal year 2020 and the succeeding years is as follows:


		Future Intangible Asset
		Amortization expense
		(in thousands)
Fiscal year:
2020		13,025
2021		11,622
2022		11,233
2023		9,962
2024		6,871
Thereafter		24,124
	$	76,837