Automated shelves – In automated shelves, the support structures are equipped with movable elements that allow the shelf to move along the floor – usually along specially adapted rails. This eliminates transport aisles (movable bases provide access to each shelf slot from a single aisle) and maximizes the use of available warehouse space. For this reason, they are most commonly installed in facilities where the cost of maintaining storage space is relatively high (e.g., cold storage units) or where quick access to the load is not essential (e.g., archives).