2-3. Army planners use the operational variables to describe an operational environment. Operational variables are those aspects of an operational environment which affect operations, and they differ from one area of operations to another. Army planners analyze an operational environment in terms of eight interrelated operational variables: political, military, economic, social, information, infrastructure, physical environment, and time (also known as PMESII-PT). As soon as a commander and staff have an indication of where their unit may deploy, they begin analyzing that location’s operational environment using the operational variables. They continue to refine and update their analysis even after receiving a mission and throughout the course of the ensuing operation. (See ADP 3-0 for additional information on the operational variables.)