Kanban is a Lean tool designed to reduce the idle time in a process. The main idea behind the Kanban system is to deliver what the process needs exactly when it needs it. In Japanesethe word "Kan" means "visual" and "ban" means "card," so Kanban refers to visual cards. Kanban is a concept related to lean and just-in-time (JIT), where it is used as a scheduling system that tells you what to supply, when to supply it, and how much to supply.