Unit load AS/RS is a system used for large and heavy loads from 500 kg and up. The parts are located at pallets on aisle racks within the storage. It is paired with a crane to handle the store and retrieval processes. Mini load AS/RS is similar to the unit load AS/RS but scaled down in terms of weight and size of parts that can be handled. Typically, parts are stored in boxes or trays in this system. Shuttle based AS/RS manages the storage via shuttles on tracks running within storage racks to store and retrieve racks and deliver them to a workstation. Carousel based AS/RS has a constant rotation of the stored products in bins or trays following a track. This can be either vertical or horizontal. Vertical Lift Modules are closed systems with a dedicated space for inserting and retrieving parts. This is done on either trays or shelves that are stored in vertical columns.