carousels
a carousels operates on a different concept than most other mechanized handing equipment. rather than require the order selector to go to the inventory storage location, the carousel moves inventory to the order selector. a carousel consists of a series of bins mounted on an oval track or rack. there may be multiple track levels, allowing for very high-density carousel storage. the entire carousel rotates, moving the selection bin to a stationary operator. the typical carousel application is for the selection of the selection of packages in such items as pack, repack, and service parts. the rationale behind carousel systems is to shrink order selection labor requirements. some carousel systems also utilize computer-generated pick lists and computer-directed carousel rotation to further increase order selector productivity. these systems are referred to as paperless picking because no paperwork exists to slow down employee efforts. a variation of the carousel system is movable racks. such racks move horizontally to eliminate the permanent aisle between the racks. this system, often used in libraries, provides more storage density but reduces picking efficiency since the racks must be moved to access specific products.