Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019	Dec. 28, 2019
Revenue	$ 17,882	$ 13,621	$ 37,142	$ 25,784
Gross profit	$ 2,453	$ 1,942	$ 5,713	$ 3,280
Gross profit margin	13.70%	14.30%	15.40%	12.70%
SG&A	$ 2,314	$ 2,450	$ 4,447	$ 4,755
Operating income (loss)	139	(508)	1,266	(1,475)
Other income, net	1	26	2	41
Interest expense, net	(36)	(4)	(41)	(6)
Tax expense	(36)	(31)	(58)	(51)
Net income (loss)	68	(517)	1,169	(1,491)
Total assets	34,516		34,516		$ 28,686
EPCM
Revenue	6,632	5,659	11,755	11,292
Gross profit	$ 646	$ 828	$ 923	$ 1,499
Gross profit margin	9.70%	14.60%	7.90%	13.30%
SG&A	$ 612	$ 589	$ 1,277	$ 1,176
Operating income (loss)	34	239	(354)	323
Total assets	7,607		7,607		6,253
Automation
Revenue	11,250	7,962	25,387	14,492
Gross profit	$ 1,807	$ 1,114	$ 4,790	$ 1,781
Gross profit margin	16.10%	14.00%	18.90%	12.30%
SG&A	$ 369	$ 390	$ 704	$ 819
Operating income (loss)	1,438	724	4,086	962
Total assets	12,241		12,241		13,603
Corporate
Revenue	0	0	0	0
Gross profit	$ 0	$ 0	$ 0	$ 0
Gross profit margin	0.00%	0.00%	0.00%	0.00%
SG&A	$ 1,333	$ 1,471	$ 2,466	$ 2,760
Operating income (loss)	(1,333)	$ (1,471)	(2,466)	$ (2,760)
Total assets	$ 14,668		$ 14,668		$ 8,830