2-21. The theater army commander and TSC commander task-organize sustainment brigades for a joint operation or campaign. +Each sustainment brigade is a multifunctional sustainment organization with a flexible headquarters capable of accomplishing multiple sustaining missions. The number of combat sustainment support battalions (CSSBs) and functional logistics battalions attached to the sustainment brigade varies with the task organization established by the ESC commander. The specific task organization of each sustainment brigade will vary based on its mission.