of processes for the development or application of such simulations. Training and Doctrine Command (TRADOC) is responsible for the development of operational system requirements, training, and doctrine for the U.S. Army. Once a weapon system has been approved for development, it is assigned to a program office headed by a program manager and supported by a staff that coordinates all aspects of the development. The various offices are grouped by type of system (e.g., electronic, combat, combat support, combat service support) and are controlled by program executive officers on the Army staff. They are reinforced by proponent organizations from TRADOC and by material developers from the U.S. Army Materiel Command. The most commonly used simulations in support of Army research, development, and acquisition are of the constructive type.
The Naval Systems Command, organized into air, surface, and subsurface systems, oversees the system requirements process, but actual development is placed in the hands of a system program office. Each such office is organized with all of the resources and organizational structure needed to control and execute program development and acquisition. Programs are organized around the fighting system, such as the Aegis class cruiser or a carrier-based attack aircraft. Typically, the system program offices develop unique simulation capabilities for their system for both analysis and training applications.
The Air Force Systems Command is organized into system program offices similar to those of the Navy and has operational commands, such as the Air Combat Command, that provide doctrine and training requirements. The Air Force acquisition process is built entirely around the weapon system, and the system program office has control of all of the development processes, including simulation and simulator development.
Analysis of advanced concepts and requirements is focused on the development and evaluation of doctrine and organizations at a stage that precedes system development. The thrust is on predicting and assessing the impact of force effectiveness outcomes that will result from new technology, changes in force structure mixes, or the integration of joint or combined forces. Users of simulations in this advanced-technology area include DARPA, the U.S. Army Concepts Analysis Agency (CAA), the Center for Naval Analyses (CNA), several Air Force analysis organizations, such as the RAND Corporation, and DoD joint task force study organizations, all of which research new defense threat issues or future service structures/requirements. While such organizations may develop new simulations through civilian contracts, they use or adapt many of the same constructive simulations used in the research, development, and acquisition area.