A mobile drive unit that freely and independently moves about a facility to transport inventory holders. The mobile drive unit may operate through communications with other drive units, or under a more centralized control of a management module. For various operating scenarios, the mobile drive unit is directed to shuffle the inventory holders in a manner that minimizes travel of the mobile drive unit, thereby improving overall system efficiency. One or more mobile drive units may be used to transport inventory holders to and from a region, and to sequentially reposition or slide each of the inventory holders within the region according to a priority ordering.