6-96. Subordinate brigades preparing their defense require significant quantities of barrier material and ammunition. The assistant chief of staff, logistics (G-4) ensures that the supporting sustainment brigade provides materiel in times and locations that expedite defensive preparations. Consumption of Class IV and V supplies in the defense is typically higher than in the offense. The division or BCT constituting the command’s forward security force or striking force require a greater amount of Class III and maintenance support than their MBA counterparts. In both cases, the more distance the forward security force and striking force must cover to accomplish their missions, the greater sustainment they require. When these two forces are located at a significant distance from the support area, establishing a forward logistics area to support the planned employment of these two forces may be necessary. The preparation phase is also a good time to provide unit replacements.