Fame at last, as an appendage. When we in Shell were looking at grocery ordering on an 'on line' that we were going to invent, we were naturally focused on single picking warehouses. Robotics were of course fundamental, but we settled on cassette dispensers, whereby manufacturers were to supply standard sized packages that were bulk broken and dispensed accordingly. Alll you then need was to tell the system which dispenser held what and belt-carry individual order "baskets" to appropriate dispensers. Arms waving around don't sound too practical, in the light of jams, misplaced feeds and so on.