The United States Department of Homeland Security, Drug Enforcement Administration and Federal Aviation Administration are among Subsystem Technologies' customers. The company's largest customer base is the U.S. federal government. It serves state and local governments, as well. Other federal government clients include the U.S. Air National Guard, Army Tank Command and Navy. Subsystem Technologies' client partnerships average over 10 years, and the company draws 80 percent of its annual business from repeat clients. Subsystem's services include asset management, business process improvement, data management, information assurance, information technology, multimedia practice, program management, radar design and implementation, RFID practice and training onsite and offsite. The company, which employs around 100, is located in Rosslyn, Va.