In Army usage, the amount of ammunition estimated to be available to sustain operations of a designated force for a specified time if expenditures are controlled at that rate. It is expressed in terms of rounds per weapon per day for ammunition items fired by weapons, and in terms of units of measure per organization per day for bulk allotment ammunition items. Tactical commanders use this rate to control expenditures of ammunition during tactical operations at planned intervals. It is issued through command channels at each level. It is determined based on consideration of the required supply rates submitted by subordinate commanders and ammunition assets available.