SMS Holdings works behind the scenes to keep public facilities across 45 US states up and running. Its Service Management Systems unit provides maintenance and housekeeping services for large buildings. Subsidiary FirstLine Transportation Security offers passenger and luggage screening at US airports, while its PrimeFlight Aviation division provides services such as baggage assistance, ground handling, aircraft cleaning, and ticket verification. Its Block by Block unit helps cities design security, cleaning, and customer service programs. In addition, the company offers security support services through Brantley Security and Valor Security Services. William T. Coakley founded the company in 1988.