FM 5-0, The Operations Process - Federation of American Scientists

Appendix I
• Operations security risk. Moving a large part of the force may attract unwanted enemy
attention. Commanders develop a plan to protect the rehearsal from enemy surveillance and
reconnaissance. One method is to develop an alternate plan, including graphics and radio
frequencies, which rehearses selected actions without compromising the actual operation order.
Commanders take care not to confuse subordinates when doing this.
• Terrain. Terrain management for a full-dress rehearsal can be difficult. The rehearsal area must
be identified, secured, cleared, and maintained throughout the rehearsal.
REDUCED-FORCE REHEARSAL
I-18. Circumstances may prohibit a rehearsal with all members of the unit. A reduced-force rehearsal
involves only key leaders of the organization and its subordinate units. It normally takes fewer resources
than a full-dress rehearsal. Terrain requirements can be the same as a full-dress rehearsal, even though there
are fewer participants. The commander first decides the level of leader involvement. Then the selected
leaders rehearse the plan while traversing the actual or similar terrain. Often commanders use this
technique to rehearse fire control measures for an engagement area during defensive operations. A reducedforce
rehearsal may be used to prepare key leaders for a full-dress rehearsal. It may require developing a
rehearsal plan that mirrors the actual plan but fits the terrain of the rehearsal.
I-19. Often, smaller scale replicas of terrain or buildings substitute for the actual AO. Leaders not only
explain their plans, but also walk through their actions or move replicas across the rehearsal area or sand
table. This is called a rock drill. It reinforces the backbrief given by subordinates since everyone can see the
concept of operations and sequence of tasks.
I-20. Reduced-force rehearsals have the following implications:
• Time. A reduced-force rehearsal normally requires less time than a full-dress rehearsal.
Commanders consider how much time their subordinates need to plan and prepare when
deciding whether to conduct a reduced-force rehearsal.
• Echelons involved. A small unit can perform a full-dress rehearsal as part of a larger
organization’s reduced-force rehearsal.
• Operations security risk. A reduced-force rehearsal is less likely to present operations security
vulnerabilities than a full-dress rehearsal because it has fewer participants. However, the number
of radio transmissions required is the same as for a full-dress rehearsal and must be considered.
• Terrain. Terrain management for the reduced-force rehearsal can be as difficult as for the
full-dress rehearsal. The rehearsal area must be identified, secured, cleared, and maintained
throughout the rehearsal.
TERRAIN-MODEL REHEARSAL
I-21. The terrain-model rehearsal is the most popular rehearsal technique. It takes less time and fewer
resources than a full-dress or reduced-force rehearsal. (A terrain-model rehearsal takes a proficient brigade
between one to two hours to execute to standard.) An accurately constructed terrain model helps
subordinate leaders visualize the commander’s intent and concept of operations. When possible,
commanders place the terrain model where it overlooks the actual terrain of the AO. However, if the
situation requires more security, they place the terrain model on a reverse slope within walking distance of
a point overlooking the AO. The model’s orientation coincides with that of the terrain. The size of the
terrain model can vary from small (using markers to represent units) to large (on which the participants can
walk). A large model helps reinforce the participants’ perception of unit positions on the terrain.
I-22. Terrain-model rehearsals have the following implications:
• Time. Often, constructing the terrain model is the most time-consuming part of this technique.
Units require a clear SOP that states how to build the model so it is accurate, large, and detailed
enough to conduct the rehearsal. A good SOP also establishes staff responsibility for building
the terrain model and a timeline for its completion.
• Echelons involved. Because a terrain model is geared to the echelon conducting the rehearsal,
multiechelon rehearsals using this technique are difficult.
I-4 FM 5-0 26 March 2010