Justification and Approval for Other than Full and Open Competition under the Title 10 U.S.C. §3406(c)(1) as implemented in Federal Acquisition Regulation (FAR) 16.507-6(b)(1) - Interest of economy an... Justification and Approval for Other than Full and Open Competition under the Title 10 U.S.C. §3406(c)(1) as implemented in Federal Acquisition Regulation (FAR) 16.507-6(b)(1) - Interest of economy and efficiency. The order must be issued on a sole-source basis in the interest of economy and efficiency because it is a logical follow-on to an order already issued under the contract, provided that all awardees were given a fair opportunity to be considered for the original order.