A method of sorting items using a dynamically reconfigurable sorting array system, wherein the system includes a plurality of destination areas arranged into a series of columns extending generally vertically, a plurality of delivery vehicles, and an event annunciation system, the method comprising the steps of:
- transferring, onto a delivery vehicle, an item to be delivered to a first destination area of the plurality of destination areas;
- driving the delivery vehicle along a path to the first destination area;
- initiating discharge of an item to the first destination area;
- upon detection of an item to be manually delivered to a second destination area of the plurality of destination areas, operating the event annunciation system to provide a first visible alert;
- upon detection of manual delivery of an item to the second destination, operating the event annunciation system to at least one of discontinue the first visible alert or provide a second visible alert visibly distinguishable from the first visible alert.