There are executive officer slots in each company, battalion, regiment, and brigade, though generally not at higher levels of command until the army level. The XO is typically the second-in-command, and serves as the day-to-day manager of the command staff. The XO is typically responsible for the management of day-to-day activities, such as administration, maintenance, and logistics, freeing a commander to concentrate on tactical/operational planning and execution and a general officer commander to concentrate on similar planning and execution at the operational-strategic level. The XO may take charge in the absence of the commander, the exception being commands with a deputy commander, although recent army command reductions have either merged the two, or eliminated the deputy.