This is part 2 of a 3-part series on special kanban cards.
In the first article in this series on special kanban cards we learned about spike cards and the various scenarios that call for their deployment. In this article we cover some important tips to keep in mind when deploying spike cards.
Spike Card Process Tips
Achieving the most favorable outcomes when using spike cards requires a disciplined process. Below are a few rules that you should always follow when using spike cards to prevent inventory traps.
- Do your best to prevent surprising your supplier with sudden demand increases. Communicate early and often with your supplier. Let them know early on what you will need and the time frame that you will need it in. Advance notice should be appreciated, but even more importantly it improves the likelihood that your inventory needs will be met on time.
- Do not deviate from Kanban Order Quantities (KOQs). Consider that your KOQ already meets Minimum Order Quantity (MOQ) and Standard Package Quantity (SPQ) requirements. Additionally, your point-of-use (POU) areas and containers are already designed to facilitate KOQ orders.
Understand that sticking to the KOQ may require you to use multiple spike cards to maintain the inventory necessary for the demand spike. This is actually a good thing! Periodically receiving a sequence of smaller (normal sized) orders, is more manageable for storage and handling than a single extra-large order would be.
Work cells will especially appreciate that the order quantity is exactly what they are used to handling and processing at a given time. Sticking to the KOQ might mean a greater number of orders to have to put through the receiving process, but the receiver will be prepared to handle standard quantities of items. That will not be the case if the receiver suddenly must find a way to process an order size three times greater than what he or she is used to.
Another reason for using KOQs is that situations that require spike cards can be time-sensitive. If you don’t order in smaller batches (such as the KOQ), you could end up inadvertently increasing the supplier lead time, so you wind up waiting much longer before moving forward with filling any of your orders. Smaller quantities will ensure that your items begin arriving at your facility sooner, which means that you can meet your own client’s needs in less time.
- Consume regular inventory before spike inventory. Treat spike cards the same way that you treat your regular kanban cards. Just like regular kanban cards, after an order is placed, a spike card should be put on the kanban board on the date that the items are due. Like regular kanban cards, spike cards will travel to the work cells with the ordered items when they arrive. However, since spike inventory is meant to be used after the regular kanban order has been consumed, it should always be placed behind or under regular inventory.
Consider, even though the parts are identical, the regular kanban card order items will be accompanied by a regular kanban card that needs to remain in regular rotation. If the spike inventory is consumed first, it will trigger another spike order. This is not good—it wrecks the order of your kanban solution triggers. This will artificially and possibly unnecessarily extend temporary spike ordering, possibly saddling you with excess inventory.
- Spike cards should never be scannable. While standard kanban cards should always be scannable (digitally, with a bar code), spike cards should never be scannable. If spike cards were digitally scannable, it would be too easy to disrupt the flow of regular kanban items.
Removing the bar code for spike cards is the best way to ensure that the cards are not going to be automatically scanned by someone who isn’t paying close attention. By making spike cards unscannable, you’re forcing additional human interaction with the card, ensuring that it gets more closely examined. This manual review is a good thing! Without additional scrutinization, you are more likely to end up with excess inventory once demand returns to normal.
- Always ensure that spike cards are visually different from regular kanban cards. Make sure that they stand out in some obvious way, such as the color of the card, its shape or its size. You want the cards to be easily recognized since you need people to notice them and review them closely. Draw attention to them!
In part 3 of this 3-part series on special kanban cards we learn more about two additional types of special kanban cards: transfer kanban cards and serialized kanban cards.