Kanban
Scan-based pull replenishment. A kanban card ties an item to a bin, and scanning it fires a purchase order or a job.
A in Carbon is a physical pull signal: a printed card (or QR code) that lives with the stock it replenishes. It ties one item to a location and storage unit, carries a reorder quantity, and — when someone scans it — creates the downstream order to refill that bin. Nobody watches a number; the card is the trigger.
This is deliberately different from a reordering policy. A policy runs inside the planning engine and reasons about on-hand levels, demand, and reorder points. A kanban is manual and physical: a person empties a bin, scans the card, and an order appears. Use a policy for planned, calculated replenishment; use a kanban for two-bin shop-floor pull where a scan should just do the thing.
What a kanban holds
Each kanban is a small record: an item, where it lives, how much to reorder, and how to reorder it.
Buy (raise a purchase order) or Make (create a job). See .Buy kanbans.Buy only.)Make scan, release the created job to the floor immediately instead of leaving it in draft. (Make only.)Make scan, drop the operator straight into the first operation in MES. Requires Auto Release. (Make only.)Make only.)The replenishment system enum has three values (Buy, Make, Buy and Make), but the kanban form only offers Buy and Make. A kanban set to Buy and Make is rejected at scan time — a single card fires one clear action, not both.
The scan flow
Every kanban card carries three scan targets, one per action: order, start, and complete. Scanning opens a URL that runs the action and redirects you into the resulting document. The QR codes are color-coded so the right one is obvious on the floor: order is black, start is emerald, complete is blue.
The order scan (the create signal) branches on the replenishment system:
Draft or Planned) purchase order for that supplier and adds a line for the kanban's quantity — or creates a new draft PO if none exists — then drops you on the purchase order. It applies the kanban's conversion factor, purchase unit, and storage unit to the line.Start and complete scans only apply to Make kanbans. They resolve the linked job's active operation and hand off to the MES operation start / complete screens, so an operator can drive the whole build from the same card that created the job.
A Make kanban links to the job it created (jobId). If you scan order again while that job is still open, Carbon doesn't create a duplicate — it routes you to a collision screen that shows the existing job and offers to remove the link so a fresh scan can start over. Once the job is completed or cancelled, the link clears automatically and the card is free to fire again.
Output format
How a card is rendered is a per-company setting, Kanban Output, with three modes:
| Mode | What a card is |
|---|---|
| QR code | A scannable QR code (the default), color-coded per action. |
| Label | A printed PDF label — six to a page — with the QR, item thumbnail, name, storage unit, quantity, and supplier. |
| URL | A copyable link that hits the same scan endpoint directly. |
For Make kanbans, the list view also surfaces the start and complete affordances; Buy kanbans show only the order signal, since there's no job to start.
Kanban vs. reordering policy
Both replenish stock, but they're different tools:
A kanban is a signal, not a plan
A reordering policy is evaluated by the planning engine, which computes suggested orders from on-hand, demand, and reorder points. A kanban skips all of that: a human scan creates a real purchase order or job on the spot. Reach for a kanban when the shop floor pulls material by hand and you want the refill to be one scan away.