text: Operational Art and Science
  is inherently joint. The combination of Army and joint sustainment capabilities enables the combatant
  commander to maximize the effect of the Army’s capabilities in an operational area. The Army’s robust
  sustainment capability assists in providing theater and port opening functions enabling joint forces to conduct
  strategic reach. Army sustainment capabilities provide the bulk of support in a theater, including ASOS, in
  the forms of executive agent, common-user logistics, lead service, and other common sustainment resources.
  ASOS enables joint forces with operational reach, freedom of action, and endurance. (See Appendix B for
  more information on ASOS.)
  STRATEGIC TO TACTICAL SUSTAINMENT
  2-127. The strategic support area describes the area extending from the JSA in a theater to the continental
  United States or another combatant commander’s AOR. The strategic support area also includes the air and
  sea ports that support the force projection, flow, and sustainment of forces into the JSA in a theater. In the
  United States, sustainment originates in the strategic support area. The strategic support area generates Army
  sustainment capabilities, which enable sustained operations through end-to-end processes that drive
  efficiencies across military Services, agencies, and industries.
  2-128. The theater army is responsible for providing support to Army forces and common-user logistics
  and support to other Services as directed by the combatant commander and other authoritative instructions.
  The TSC is assigned to the theater army. As directed, the TSC provides lead service and executive agency
  support for designated logistics and services to other government agencies, multinational forces, and
  nongovernmental organizations. The TSC is the Army’s command for the integration and synchronization of
  sustainment in the AOR. A MEDCOM (DS) is also assigned to the theater army. It is responsible for
  command and control, integration, synchronization, and execution of Army Health System support in the
  AOR with strategic ties to the Defense Health Agency. The MEDCOM (DS) commander coordinates with
  the theater army surgeon to provide Army Health System support in the AOR.
  2-129. Field army and corps headquarters are responsible for the integration and synchronization of
  operational sustainment in their assigned AO. A corps is supported by its assigned ESC. When constituted,
  a field army receives an attached ESC to provide sustainment support. The ESC will typically command and
  control sustainment units supporting the rear area while providing general support to the forward units. The
  ESC commander may perform the duties of deputy commanding general (support) if directed by the
  commander. The ESC assists the sustainment cell with planning, coordinating, and executing sustainment
  operations.
  2-130. Division headquarters are responsible for the integration and synchronization of sustainment in their
  assigned AO. The division’s assigned, task-organized division sustainment brigade provides general support
  for all division units. The division sustainment brigade coordinates and synchronizes tactical-level
  sustainment operations to meet current and future operations. Additional modular combat sustainment
  support battalions and companies may be attached to the division sustainment brigade to sustain large-scale
  combat operations. (See FM 4-0 for a detailed description of sustainment at different echelons.)
  PLANNING CONSIDERATIONS
  2-131. Sustainment enables the success of campaigns and operations by providing commanders the
  operational reach, freedom of action, and endurance to achieve operational objectives. Sustainment should
  be planned in concert with operations. At the operational level, this requires a detailed understanding of all
  sustainment requirements, as the overall feasibility of an operation is often a function of its sustainability.
  Some of the major operational planning considerations for sustainment are—
  * Concurrent planning.
  * Sustainment force flow.
  * Sustainment nodes and modes.
  Concurrent Planning
  2-132. It is important for sustainment planners to conduct concurrent planning with operational planning.
  Commanders plan for sustainment as the operational concept is developed. This ensures their courses of
  action are feasible from a sustainment perspective, allows commanders to request additional assets if