text: Relief in Place
  combat, functional, and multifunctional support and sustainment elements to remain with the incoming unit
  until completing the necessary plans. The incoming unit receives current intelligence, operations, and
  sustainment information from the outgoing unit as well as from common higher echelon headquarters,
  adjacent units, and subordinate elements. The complexity of a relief in place requires extensive liaison and
  reconnaissance. Exchanging information about enemy forces and civilian situations, friendly dispositions,
  terrain analysis, and fire support and obstacle plans—coupled with reconnaissance—helps relieving units
  plan and execute the mission.
  15-10. The relief is a vulnerable operation. The units involved concentrate on security while preparing for
  and executing the operation. The intent of the operation is to complete the relief without discovery by enemy
  forces. Consequently, units typically plan reliefs for execution during periods of reduced visibility such as
  night or fog. Concealing the relief from enemy forces is a primary concern when the unit conducts the relief
  as part of an economy of force measure to free forces for other operations. Enemy forces should perceive
  only one unit’s command structure in operation—the outgoing unit—until the operation is complete. This
  requires a detailed knowledge of friendly vulnerabilities. If the enemy should detect the relief and attack
  during the transition, the outgoing unit commander controls all units in the assigned area unless otherwise
  specified in the operation order.
  15-11. Generally, as soon as the mutual higher echelon headquarters issues the warning order, the
  commander of the incoming unit co-locates the tactical command post—with the main command post of the
  outgoing unit. At a minimum, the incoming unit establishes communications and liaison with the outgoing
  unit. The warning order designates the time of relief, relieving and relieved units, and sequence of events. It
  specifies the future missions of the outgoing unit, route priorities, any restrictions on advance parties, any
  extraordinary security measures, and the time and place for issuing the complete order. During a relief in
  place, commanders and leaders from the incoming unit conduct a reconnaissance of the area they are to
  assume. The reconnaissance focuses on routes into the area, routes to positions, the positions themselves, the
  current disposition of the outgoing unit, and any obstacles that could affect troop movement.
  15-12. The two commanders of the units conducting the relief decide on a time or an event that initiates the
  passage of command. This allows the smooth transition of command from one commander to another.
  Normally, this occurs when the frontline subordinate commanders have assumed responsibility for their
  respective assigned areas, and the incoming commander has established sufficient communications to control
  the operation. Regardless of their parent organization, all units in the assigned area come under the
  operational control of a single commander if the units come under attack or when a specified event occurs
  during the relief.
  15-13. The fire support coordinators establish FSCMs and identify artillery and other available fire support
  units to support the relief. The incoming unit adopts the fire plan of the outgoing unit, and both units support
  the relief. This maintains fire support if enemy forces detect the relief and try to exploit the situation. Units
  plan their fires to deceive enemy forces and expedite the relief. Units also ensure that they maintain normal
  activity patterns. For example, a unit continues to expend the same average number of artillery rounds per
  day during the relief that it expended before the initiation of the relief. Units do not relieve fire support or
  functional and multifunctional support and sustainment units at the same time as the maneuver units they
  support. They relieve those organizations before or after the primary relief operation.
  15-14. The relief plan specifies the method used in relieving artillery units. If terrain allows, incoming
  artillery units do not occupy previously used firing positions. Instead, incoming firing units establish firing
  positions near the firing positions of the outgoing unit and carefully integrate their fires with the relieved
  unit. Occupying firing positions at night or during periods of poor visibility enhances OPSEC.
  15-15. Units ensure air and missile defense units provide area coverage of the incoming forces. Typically,
  air defense units focus their available assets at critical sites, such as identified choke points, BPs, assembly
  areas, and command posts.
  15-16. Handover of obstacles is a complex procedure. The incoming unit verifies the obstacle records of
  the outgoing unit. Initially, the engineer priority is to provide mobility to the incoming unit. It focuses on the
  routes and lanes leading into the assigned area. Once the relief occurs, priority of the mobility and
  survivability effort transitions to support the incoming unit’s continuing mission. Units may require
  additional engineer support to assist with survivability tasks to support the incoming force.