A kanban card is a visual signal used in lean manufacturing and inventory management to trigger replenishment. The word kanban (看板) is Japanese for “signboard.” In a pull-based system, material is only ordered when downstream consumption creates demand — and the kanban card carries that signal from point of use back to the supplier or stockroom.

Two-Bin System

Each part has two bins: active and reserve. When the active bin empties, the operator pulls the kanban card and sends it to purchasing. The reserve keeps production running while the order is fulfilled. Once replenishment arrives, the cycle repeats. The card encodes everything needed: part number, supplier, order quantity, bin location, and a barcode or QR code for scanning into an ERP or WMS.

Reorder Point Formula

ROP = (daily usage × lead time) + safety stock. The order quantity is typically the EOQ or supplier minimum. Pair kanban cards with SPC to track consumption variability and set data-driven reorder points.

Card Sizes

• CR80 (3.375 × 2.125 in) — credit-card size, fits badge holders and card racks.
• Half-Letter (3.5 × 5.5 in) — classic kanban card size with full barcode.
• Index 4×6 (4 × 6 in) — large-format for wall boards and visual management.

Barcodes and QR Codes

Code128 barcodes for scanner stations, plus optional QR codes encoding either a reorder URL (scan-to-order) or full JSON card data for WMS/ERP integration. All render at 300 DPI for sharp card-stock printing.