Prioitize by Content


I would like to know if I can prioritize a task depending on the content of a buffer or a rack.

Context Situation: I have a human resource which is being used to transport items from three different racks (or buffers), and I need the human to pick items from the rack with more items ( with more content on it). How can I tell the Task Controller, or the Human, or the Rack, that I need the items from the most occupied rack. Thanks in advance.