TRADOC Pamphlet (TP) 525-4-1, The U.S. Army Functional Concept for Sustainment (AFC-S) Feb 2017 The U.S. Army is the Nation's principal land force organized, trained, and equipped for prompt and sustained combat on land. Army organizations provide foundational sustainment capabilities to the joint force. Sustainment provides the endurance required to operate in sufficient scale over ample duration. Joint and Army commanders rely on logistics, personnel services, and health service support to maintain operations until mission accomplishment against determined and capable enemies. Future armed conflict will require Army sustainment forces to conduct precision, manned, unmanned, and autonomous air and surface (including subterranean), delivery of supplies, services, and equipment. A combination of logistics demand reduction and novel distribution capabilities is essential to enabling multi-domain battle and semi-independent operations. TRADOC Pamphlet (TP) 525-4-1, The U.S. Army Functional Concept for Sustainment (AFC-S), expands on sustainment required capabilities identified in TP 525-3-1, The U.S. Army Operating Concept: Win in a Complex World (AOC), TP 525-3-6, The U.S. Army Functional Concept for Movement and Maneuver (AFC-MM), and the TRADOC Multi-Domain Battle: Combined Arms for the 21st Century White Paper. The AFC-S describes how future Army forces sustain freedom of movement and action across multiple domains. While technology is a central sustainment enabler, adaptive and innovative leaders, Soldiers, and teams will remain the most critical requirement to provide the right sustainment at the right time, location, and quantity. Because delivery timeliness is critical to uninterrupted operations, the future Army realizes mission command with communication and information systems that provide a sustainment common operating picture that allows leaders from the strategic level agency to the tactical level to anticipate requirements and improve responsiveness. Because enemies will act to disrupt sustainment, every echelon maintains scalable sustainment capabilities to preserve freedom of action even if logistical support slows.