Army Techniques Publication (ATP) 4-94 describes the organization, mission, and operations of the theater sustainment command (TSC). It provides fundamental guidance for the employment of the TSC and an expeditionary sustainment command (ESC) during unified land operations. This manual describes the roles and responsibilities of the TSC and ESC during unified land operations. It describes the organization and functions of the staff to include roles, capabilities, limitations, and dependencies. The manual also provides information on strategic partners that work closely with a TSC and during all phases of an operation. This doctrine is not intended to cover garrison operations, but should serve as a guide for training and operations in garrison to prepare for unified land operations. This publication provides guidance for Army commanders, geographic combatant commanders (GCCs), joint force commanders (JFCs), and sustainers throughout the Army. This ATP serves as an authoritative reference for students and personnel who: -Develop doctrine materiel (fundamental principles and TTP) and force structure. -Develop institutional and unit training. -Develop standing operating procedures (SOP) for unit operations. -Commanders, staffs, and subordinates ensure their decisions and actions comply with applicable U.S., international, and, in some cases, host-nation laws and regulations. Commanders at all levels ensure their Soldiers operate in accordance with the law of war and the rules of engagement. (See Field Manual FM] 27-10.) ATP 4-94 uses joint terms where applicable. Selected joint and Army terms and definitions appear in both the glossary and the text. ATP 4-94 does not introduce any new terms, rescind any terms or modify any terms. ATP 4-94 applies to the Active Army, Army National Guard/Army National Guard of the United States, and United States Army Reserve unless otherwise stated. The proponent of ATP 4-94 is the U.S. Army Training and Doctrine Command. The preparing agency is United States Army Combined Arms Support Command (USACASCOM) and Sustainment Center of Excellence.