A kanban is an authorization to produce goods or withdraw goods from a supply bin. A kanban is used in a just-in-time production environment, where a customer order or the consumption of goods is the trigger to produce more goods. A kanban can take many forms, such as a colored card, a bin, an e-mail, or some alternative form of visual signal. Kanbans can be used internally in a production process, as well as with suppliers to order more goods.