Below the Combatant Commands echelon, Division commands will command and control their combat and support brigades. Divisions will operate as plug-and-play headquarters commands (similar to corps) instead of fixed formations with permanently assigned units. Any combination of brigades may be allocated to a division command for a particular mission, up to a maximum of four combat brigades. For instance, the 3rd Infantry Division headquarters could be assigned two armor brigades and two infantry brigades based on the expected requirements of a given mission. On its next deployment, the same division may have one Stryker brigade and two armor brigades assigned to it. The same modus operandi holds true for support units. The goal of reorganization with regard to logistics is to streamline the logistics command structure so that combat service support can fulfill its support mission more efficiently.