REVENUE RECOGNITION (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Total revenue	$ 11,079	$ 17,882	$ 23,528	$ 37,142
Fixed-Price Revenue
Total revenue	6,528	10,022	14,793	17,922
Time-and-Material Revenue
Total revenue	$ 4,551	$ 7,860	$ 8,735	$ 19,220

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details