To fully achieve a pull process across your entire production, the “ordinary” Kanban process will be stretched to its limits. However, what is the Heijunka board and how does it help us in terms of a pull process inside a factory? Let’s have a few words about that lean tool.
Heijunka Board – The next Level of Kanban
What is the Heijunka Board?
Kanban is one of the magic terms when talking about lean and lean manufacturing. However, it has its limits. To produce according to the customer needs, further information have to be passed towards the upstream processes (upstream processes = process steps sequenced before the observed process step, e. g. an pre-assembly station is an upstream process of a final assembly station). To do so, the Heijunka board comes into play.
The Heijunka board is quite similar to a Kanban board but has some additions to its. Though the board is linked to the idea of a production leveling, the board itself does not level any production. It focus’ on visualizing and controlling the shop floor instead.
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Heijunka Board – But how do I implement it?
To make a start, the Heijunka board is divided into 24 sections (single boxes in which you can place a Kanban card). Each section contains the production orders for 1 particular hour, from first shift 6am to first shift 6am the next day. The production orders for that 1 hour is written on a Kanban card (similar to the one on the picture below).
Let’s say we want to produce 10 parts each hour. For that purpose, we place Heijunka cards inside each section like in the picture below. The card contains all information required to produce 10 parts and works according to a production order.
Each cycle the dedicated line Feeder, better the Mizusumashi (or water spider), picks a card from the box. Then, he picks all material required to produce the 10 parts mentioned on the card from the warehouse, delivers all materials to the production line and handovers the Heijunka card to the line operators. The line operators then have all they need for the next set of parts (10 parts in particular) for the next hour.
The Heijunka board itself acts as a tool of process visualization. In case of breakdowns, the line will stop operating. That will lead to a delay of cards picked on the Heijunka board. If no cards are picked from the board, you will realize a deviation from the time slot given by the section and the actual time instantly! For example: If it is 10am and the production line is delayed, you will see Kanban cards still placed in the board of before 10am, e. g. 9am, 8am and so on. In that case, you will realize delays instantly just by checking the board.
To step deeper into the Heijunka tool, download the free e-book.
The Lean Toolbox – Getting started with Heijunka
As the Heijunka board is a quite powerful tool, it took a major part in the Lean toolbox we prepared for you here in more details. Feel free to download the toolbox and start thinking about how you finally can implement the foundation of a lean production system on your shop floor.