Introduction to Kanban

Learn about Kanban.

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Kanban

The word Kanban (看 板, also かんばん) (English: sign, index card) is a signal designed to trigger an event, and it can be an empty space, an empty bin, a piece of paper, an electronic signal, or an icon.

Kanban is a Lean tool that supports just-in-time production (JIT)Just-in-time (JIT) manufacturing is a production model in which items are created to meet demand, not created in surplus or in advance of need. as opposed to Material Requirements Planning (MRP) and batchingA Material Requirements Planning (MRP) system is a planning and decision-making tool used in the production process which analyses current inventory levels vs production capacity and the need to manufacture goods, based on forecasts..

The technique was devised by Taiichi Ohno, the godfather of Toyota Production System (TPS), to enable just-in-time production. Kanban facilitates inventory management by providing signs or signals for replenishment. According to Taiichi Ohno, Kanban is a means through which JIT is achieved.

Kanban is a visual management tool to help prevent the waste of overproduction. It identifies delays in the process and is also able to detect when processes are producing ahead of schedule.

There are additional benefits of Kanban, like:

  • Increased flexibility to meet customer demand
  • Reduction in scheduling by production control and manufacturing
  • Competitive advantage by sequencing shipments to customers to ensure they receive what they want, when they want it, and in the order they want it

The simplest type of Kanban is called a two-bin system.

A two-bin system is composed of two separate bins containing the same parts, with one bin placed behind the other.

When the first bin empties, the next full bin slides down. The empty bin becomes the Kanban signal or trigger visually, indicating that the bin needs to be replenished. The empty bins are then collected, taken to the stock room (or sent back to the supplier), and refilled. The new bin of materials is then returned to the original location in the area.

This is called a withdrawal kanban system.

Kanban systems can also utilize card systems.

In this context, the card is taken from the empty bin and placed in a holder (to be ordered). This is called a Kanban post. At certain frequencies during the day, the material handler comes and collects the cards in the post. The cards are used to reorder the parts from the supplier. Once the material is ordered, the card is placed back in the Kanban post in the ordered slot. When the new bin of materials arrives, the card from the reordered slot is placed on the arriving bin of materials. The new bin of materials is returned to the original location in the area.

Kanban system

A Kanban system aims to control the flow of material by providing inventory as a buffer to synchronize two disconnected processes. Kanban systems regulate the inventory in a production system as the volume or rate of the process changes. One piece of paper provides the information (of production quantity, time, method, sequence, or transfer quantity, transfer time, destination, storage point, transfer equipment, container, etc.) clearly for grasping at one glance.

Kanban cards

Kanban cards are normally paper-based cards that are used to propagate three types of information:

  1. Pickup information
  2. Transfer information
  3. Production information

Kanban replenishment

Kanban systems can be replenished in two ways:

  1. Constant time means they are replenished at the same time each day or several times a day. This is similar to grocery store shelves being restocked each night.
  2. Constant quantity is similar to the two-bin system. It may empty out at any time, and we refill it with the same quantity every time.