A storage method in which pallets, cases, or cartons are stacked upward from the floor to whatever practical height is available without the use of shelves.
An upstream work center that is not permitted to produce because of a full queue at a downstream work center or because no kanban authorizes production.
The condition requiring a work center that has parts to process to remain idle as long as the queue to which the parts would be sent is full, or kan-bans authorizing production are not present.