What is Kanban in TPS?
A Kanban is a signaling device (usually a physical card in a clear plastic envelope) that instructs the moving or creating of parts in a “pull” production system, invented and developed as part of the Toyota Production System (TPS). Before getting into Kanban in software development, here I take a close look at its original usage i.e. Kanban in TPS. Kanban’s aim is to minimize WIP (Work-In-Process), or inventory, between processes by making sure that the upstream process produces parts only if its downstream process needs it. “Pull” means that the downstream workers withdraw or “pull” the parts they need from their upstream processes. Figure 1 Kanban and Pull Production Figure 1 is an abstract model of a Kanban system. Illustrated in it are two processes, an upstream and a downstream process, where the upstream process supplies parts (items) to the downstream. In order to supply products to the final customer, the process needs to produce parts and make them flow to the downstream, but
