We account for goodwill and other intangible assets in accordance with the provisions of ASC 350 and account for business combinations using the acquisition method of accounting and accordingly, the assets and liabilities of the entities acquired are recorded at their estimated fair values at the acquisition date. Goodwill is the excess of purchase price over the fair value of tangible and identifiable intangible net assets acquired in various business combinations. Goodwill is not amortized but is subject to annual impairment testing. Our annual impairment testing is performed as of August 1. Testing is done more frequently if an event occurs or circumstances change that would indicate the fair value of a reporting unit is less than the carrying amount of those assets. We assess the fair value of reporting units on a non-recurring basis using a quantitative analysis that uses a combination of the discounted cash flow method of the Income Approach and the guideline public company method of the Market Approach, and compare the result against the reporting unit’s carrying value of net assets. The implied fair value of our reporting units is determined based on significant unobservable inputs, as discussed below; accordingly, these inputs fall within Level 3 of the fair value hierarchy.

The discounted cash flow method (Income Approach) uses assumptions for revenue growth, operating margin, and working capital turnover that are based on management’s strategic plans tempered by performance trends and reasonable expectations about those trends. Terminal value calculations employ a published formula known as the Gordon Growth Model Method that essentially captures the present value of perpetual cash flows beyond the last projected period assuming a constant Weighted Average Cost of Capital (WACC) methodology and growth rate. For each reporting unit, a sensitivity analysis is performed to vary the discount and terminal growth rates in order to provide a range of reasonableness for detecting impairment. Discount rates are developed using a WACC methodology. The WACC represents the blended average required rate of return for equity and debt capital based on observed market return data and company specific risk factors.

In the application of the guideline public company method (Market Approach), fair value is determined using transactional evidence for similar publicly traded equity. The comparable company guideline group is determined based on relative similarities to each reporting unit since exact correlations are not available. An indication of fair value for each reporting unit is based on the placement of each reporting unit within a range of multiples determined for its comparable guideline company group. Valuation multiples are derived by dividing latest twelve-month performance for revenues and Earnings Before Interest, Taxes, Depreciation and Amortization (EBITDA) into total invested capital, which is the sum of traded equity plus interest bearing debt less cash. These multiples are applied against the revenue and EBITDA of each reporting unit. While the implied indications of fair value using the guideline public company method yield meaningful results, the discounted cash flow method of the income approach includes management’s thoughtful projections and insights as to what the reporting units will accomplish in the near future. Accordingly, the reasonable, implied fair value of each reporting unit is a blend based on the consideration of both the Income and Market approaches.

An impairment charge is recorded for the amount by which the carrying value of the reporting unit exceeds the fair value of the reporting unit, as calculated in the quantitative analysis described above. Based on our annual impairment tests in 2019, 2018 and 2017, the fair value of each reporting unit exceeded its carrying value, and accordingly we did not record any goodwill impairment charges in 2019, 2018 or 2017.

Our reporting units are the Adhesive Dispensing Systems segment, the Industrial Coating Systems segment and one level below the Advanced Technology Systems segment.

	Adhesive Dispensing Systems			Advanced Technology Systems			Industrial Coating Systems		Total
Balance at October 31, 2018	$	388,991		$	1,194,969		$	24,058	$	1,608,018
Acquisitions		—			9,225			—		9,225
Currency effect		(1,588	)		(916	)		—		(2,504	)
Balance at October 31, 2019	$	387,403		$	1,203,278		$	24,058	$	1,614,739

	Adhesive Dispensing Systems			Advanced Technology Systems			Industrial Coating Systems		Total
Balance at October 31, 2017	$	392,295		$	1,172,857		$	24,058	$	1,589,210
Acquisition		—			24,679			—		24,679
Currency effect		(3,304	)		(2,567	)		—		(5,871	)
Balance at October 31, 2018	$	388,991		$	1,194,969		$	24,058	$	1,608,018

Accumulated impairment losses, which were recorded in 2009, were $232,789 at October 31, 2019 and October 31, 2018. Of these losses, $229,173 related to the Advanced Technology Systems segment and $3,616 related to the Industrial Coating Systems segment.

	October 31, 2019
	Carrying Amount		Accumulated Amortization		Net Book Value
Customer relationships	$	480,007	$	173,996	$	306,011
Patent/technology costs		154,735		71,663		83,072
Trade name		96,655		41,303		55,352
Noncompete agreements		11,540		10,406		1,134
Other		1,400		1,394		6
Total	$	744,337	$	298,762	$	445,575

	October 31, 2018
	Carrying Amount		Accumulated Amortization		Net Book Value
Customer relationships	$	480,404	$	137,640	$	342,764
Patent/technology costs		153,602		59,845		93,757
Trade name		96,433		34,768		61,665
Noncompete agreements		11,469		9,919		1,550
Other		1,386		1,381		5
Total	$	743,294	$	243,553	$	499,741

Amortization expense for 2019, 2018 and 2017 was $54,790, $55,448 and $44,907 respectively.

Year	Amounts
2020	$	55,241
2021	$	49,799
2022	$	45,794
2023	$	44,822
2024	$	42,109