This report describes the results of the first phase of a domain analysis performed by the SEI's Domain Analysis Project. The report establishes the context and scope of the movement control domain within command and control (C2) systems and, in particular, ATCCS. It discusses the purpose of a domain analysis and presents an overview of the method being used to perform the analysis. The report describes both the Army's use of ATCCS in achieving the Army mission and the ATCCS software development strategy. A brief description of Army C2 systems lays a foundation for defining movement control and its context in the ATCCS structure. Within this context, the report identifies the key areas within movement control that will be explored during the remainder of the domain analysis. The report also describes the approach for performing the analysis and includes appendices providing additional information about ATCCS, relevant terms, and acronyms.