Disclosed are systems and methods for an automated materials handling facility. The automated materials handling facility uses a series of automated devices, such as automated guidance vehicles, mobile drive units, robotic arms, automated sorters, etc., to facilitate item receive, stow, pick, shipping and other aspects of materials handling. The automated devices are controlled by a materials handling control system that sends instructions to the various devices to coordinate operation of those devices and to coordinate flow of items through the materials handling system.