The monograph addresses the ADPE planning and selection experiences of a newly established data processing installation, and US Army Management Systems Support Agency (USAMSSA), as it adjusted to its assigned mission of support to an equally new major staff organization, the Office of the Assistant Vice Chief of Staff, Headquarters, Department of the Army. The general background of events leading to USAMSSA's activation in April 1967 is also presented, along with the more detailed history of its ADPE selection experiences since that date. (Modified author abstract).