(Central Computer and Telecommunications Agency, London, www.ogc.gov.uk) An agency of the U.K. government's Office of Government Commerce that has been providing IT advice and guidance to the public sector for over 25 years. CCTA has also taken a lead in bringing public and private sector organizations together to develop such world class "best practice" methodologies for IT professionals as SSADM for systems analysis and design, PRINCE 2 for IT and business project management and ITIL for IT service management. See ITIL and PRINCE 2.