Justification for Other than Full and Open Competition notice. The Defense Threat Reduction Agency (DTRA) contracting activity proposes to procure, without using full and open competition, a continuin... Justification for Other than Full and Open Competition notice. The Defense Threat Reduction Agency (DTRA) contracting activity proposes to procure, without using full and open competition, a continuing effort entitled “Research & Development Directorate Advisory and Assistance Service Support” via a contract modification to the current Research & Development Advisory and Assistance Services contract with Systems Planning and Analysis, Inc. (SPA).