Revenue (Tables)

6 Months Ended

Jun. 30, 2019

The following table represents a disaggregation of revenue by type of goods or services for the three and six months ended June 30, 2019 and 2018, along with the reportable segment for each category:

(in thousands)

	Three months ended June 30,				Six months ended June 30,
	2019		2018		2019		2018
Performance Improvement Solutions segment
System Design and Build	$	5,595	$	7,300	$	12,037	$	14,795
Software		635		546		1,384		1,415
Training and Consulting Services		6,780		3,018		11,779		4,555

Nuclear Industry Training and Consulting segment
Training and Consulting Services		10,448		13,834		20,452		26,828

Total revenue	$	23,458	$	24,698	$	45,652	$	47,593

Balance of Contract Liabilities and Revenue Recognized in Reporting Period

The following table reflects the revenue recognized in the reporting periods that were included in the contract liabilities from contracts with customers:

(in thousands)

	Three Months Ended June 30,						Six Months Ended June 30,
	2019			2018			2019		2018
Revenue recognized in the period from amounts included in Billings in Excess at the beginning of the period		$	2,813		$	2,738	$	7,853		$	7,954