SDI was incorporated in 1979 in Gainesville, FL by two professors at the University of Florida with a goal to support government aviation project offices. In 1984, Steve P. Smith, now-retired SDI Vice President, left his position as Chief, Technical Management Division, TADS/PNVS Project Office, to found SDI's Aviation Technical Center in St. Louis, MO. In 1988, three government senior executives left their positions to join SDI's small Huntsville, AL office and set up their respective technical divisions in Huntsville.