External Kanban
External Kanban is a pull-based replenishment system where a consumption signal from an internal supermarket, line-side bin, or supply area triggers replenishment from an outside supplier rather than from an internal process. In SAP-oriented usage, it is a Kanban replenishment strategy for external procurement; the control cycle defines container count, kanban quantity, and external procurement settings, aligning inventory to actual consumption and reducing replenishment lead time.
On the shop floor, external kanban is attached to fixed-quantity containers at the point of use. When operators consume the last unit, the card or electronic signal is removed and transmitted to the supplier, creating a replenishment request tied to real usage rather than forecasted demand. In warehousing and raw-material staging, the kanban signal governs movement from a supplier-managed inbound area or supermarket to the line-side buffer, supporting controlled WIP and raw-material availability while preventing overstock. In SAP external procurement designs, the control cycle, replenishment strategy, and goods receipt step convert the kanban signal into procurement and inbound processing; scheduling agreements are recommended for vendor information. The loop is most effective when the supplier responds in a tight time window, because it assumes repeatable demand, stable container sizes, and disciplined receiving.
- Signal lag causing line stoppage: If the card is removed, scanned, or transmitted late, replenishment arrives after safety stock is exhausted, so the point of use runs dry and the line stops. Discipline in signal handling prevents this.
- Wrong container sizing or kanban quantity: When the kanban quantity does not match actual consumption and supplier lead time, the loop either floods the supermarket with excess inventory or empties too fast and creates repeated expedites and shortages.
- Receiving and status-control failures: If inbound receiving does not close the kanban signal, post the goods receipt, or update container status, the system shows false empties or false availability, breaking replenishment logic and causing duplicate or missed replenishment orders.
Is external Kanban the same as internal Kanban?
No. Internal Kanban replenishes within the plant, while External Kanban extends the pull signal to an external supplier or external logistics node.
Does External Kanban always create a purchase requisition or MRP element?
Not necessarily. SAP documentation distinguishes kanban-controlled replenishment from MRP-style replenishment and notes that, in one strategy, no replenishment element is created from the kanban signal itself; external procurement with scheduling agreements is commonly recommended.
What is the primary inventory-management purpose of External Kanban?
To hold the minimum necessary raw-material or component stock while ensuring the next container is replenished strictly by actual consumption, not by a forecast push cycle.