In September 1994, EDS of Chippenham, Wiltshire was awarded a contract by the U K Ministry of Defence to deliver the advanced, secure Command Information System Infrastructure for the Allied Command Europe Rapid Reaction Corps, IARRCIS.IARRCIS exemplifies the British Army's ambition to introduce modern command information systems to the battlefield. It provides complete office automation support to ARRC headquarters staff at several locations and to liaison officers attached to the participating national and multinational divisions. It is designed to facilitate the speedy compilation and distribution of operational orders and assessments of reports and returns which may be required to support intensive land warfare. Ease of deployment, use and system support are of paramount importance and are key considerations in the EDS system.IARRCIS pioneered the combination of commercial-off-the-shelf information technology with a robust, tactical wide area network, providing a secure environment in which to process classified data. EDS will integrate around 20 commercial software packages. The EDS solution is transportable and has shown to be easily and rapidly deployable. The system will support over 200 headquarters staff users and over 100 liaison officers.In November 1997, EDS was awarded a new contract called Enhanced IARRCIS or E-IARRCIS to integrate an all new Windows NT solution onto the current IARRCIS architecture and to supply additional high-performance machines.
Initial deliveries began in 1995, leading to full operational capability in April 1996, including immediate use by the ARRC in HQ IFOR, Bosnia. Since then, the system is being more widely supplied throughout the British Army where it is known as the Army Tactical Computer System (ATacCS). E-IARRCIS began delivery in 1998.