This is part 5 of a 6-part step-by-step series on kanban deployment. This article covers specifics of properly deploying kanban cards for inventory items with Empty-a-Bin (EaB) replenishment triggering.
Empty-a-Bin (EaB) Cards
Empty-a-Bin (EaB) kanban systems are interesting in the way that every single item in stock will get associated with a card during kanban card deployment. Since there are cards that will be associated with a complete Kanban Order Quantity, it might be hard to grasp that items will get assigned to a card even if there are not enough to make a full order. If there are 51 items in stock and the KOQ is 25, that one item gets its own card even though the other two cards each have 25. In fact, a minimum of two cards is needed even if the total on-hand balance is only KOQ + 1.
To distribute these cards, you first need to separate the items that you have on hand into groups that equal the Kanban Order Quantity.
Every full group gets a card, and any partial group will also get a card. Your items may run out before your cards do. You should scan any cards that are left over after giving every item a card. These will trigger more orders, and the scanned cards can be placed on the delivery date on the kanban wall to wait for those items.
You just might end up with the opposite imbalance – having more items on hand than can be distributed to the number of cards in that solution. In this case, the items that are not matched to a card will be managed as excess inventory. Excess inventory must be consumed before any new orders are processed. You’ll have to implement temporary special procedures for dealing with cards as the items are consumed.
This is how to handle excess inventory:
- Place the standard Kanban Quantity bins at the Point of Use along with their assigned cards. As the bins are emptied, the cards are used to replenish the supply. Since you don’t want to initiate new purchase orders or manufacture orders, make sure everyone knows that they should not scan the bar codes on the cards. Either cover it up completely with a sticker or place a very prominent label on the card. The cards will still be used for their intended purpose – to trigger the flow of another bin of items into the work-cell. However, instead of coming from a supplier, the items will come from the excess inventory until it has been fully consumed.
- Designate a separate area for storing the excess inventory. The chosen location should be organized, clearly labeled and relatively easy to get to.You might think the easiest location to get to would be where the other on-hand inventory is kept (at the Point-of-Use). It’s important that you do not try to keep more inventory at the POU than the standard bin or two (or whatever reasonable quantity has been predetermined). Trying to make room for excess inventory at the POU is a waste. Not only will time be spent creating storage for a temporary excess in items, but the time will be wasted again after the excess is gone and the work-cell needs to be reconfigured to maximize efficiency for the correct inventory sizes.
- While working through the process of bleeding down the excess inventory, auditing is essential. You need to keep track of the items closely so that you are ready to use cards to signal supplier orders as soon as they are needed.
When items are in a steady state, the Empty-a-Bin process is pretty simple.
- Cards will be with the active bin, with the bin that will be active next or on the kanban board waiting for an order. Once a card is with a bin, the card stays there until the bin is emptied.
- Scan the card and hang it on the kanban board when the bin is finally empty. At that point, the scanned card goes to the kanban board, and the second card and the new bin move up to become the active bin.
- One card should always be active and on the floor. If both cards are on the kanban board, it means a stock out has occurred.
In the final part of this series we’ll explore the specifics of properly deploying kanban cards for inventory items with Break-a-Bin (BaB) replenishment triggering.