Barcode Kanbans = Awesomeness.
Daily Consumption (d) = 1000 pcs/day
Std Deviation (s) = 300 pcs
Lead Time to Replenish (t) = 3 days
Kanban Quantity (q) = 48 pieces
So using the formula [(d*t)+(1.65*s)]/q with 1.65 being the z value for 95% confidence (normality assumed), I calculated that we would need 73 kanbans cards. 73!! How do you manage 73 kanban cards??
Instead of making 73 physical kanban cards, I developed a VB.net application that utilizes a networked SQL database. Basically, the customer process scans a barcode when they pull a part and it instantly pops up at the supplier process saying they need one. The tricky part was setting up the software to do a batch kanban. The kanban quantity was 48 pieces but the signal quantity was sometimes 10, 20 or 30 peices. So the software had to keep track of pieces requested until 48 was reached. The requests will queue at the supplier until he builds the item and sends it along. At this point, he'll indicate on the software that the order has been fulfilled.
I understand that Kanbans are best when they are visual and physical, but the barcode Kanban has worked great in this scenario. It eliminates the wasted travel and lag time and provides instantaneous feedback to the supplier.