Department of Defense Use of Other Transaction Authority: Background, Analysis, and Issues for Congress [Updated February 22, 2019] [open pdf - 2MB]
From the Document: "The Department of Defense (DOD) obligates more than $300 billion annually to pay for goods and services (including research and development). Most of these acquisitions are governed by numerous statutes and regulations found in Title 10 of the United States Code, the Federal Acquisition Regulation (FAR), and the Defense Federal Acquisition Regulation Supplement (DFARS). DOD can also enter into certain transactions without triggering most of the standard acquisition statutes and regulations by using other transaction (OT) authorities. In recent years, Congress has expanded these authorities and DOD is increasingly using OTs for research, prototyping, and production. This report examines (1) how OTs work, (2) why they were established, (3) potential benefits and risks of using OTs, and (4) whether there are data available against which to measure their effectiveness."
CRS Report for Congress, R45521
Congressional Research Service: https://crsreports.congress.gov/