Defense Primer: Lowest Price Technically Acceptable Contracts [Updated January 31, 2020] [open pdf - 450KB]
From the Background: "When procuring goods or services, the Department of Defense (DOD) generally seeks to obtain the best value for the government by encouraging full and open competition, as required by the 1984 Competition in Contracting Act (P.L. 98-369, also known as CICA). 'Full and open competition' occurs when all eligible prospective contractors are permitted to submit bids or proposals in response to a proposed contract action."
CRS In Focus, IF10968
Congressional Research Service: https://crsreports.congress.gov/