Supplier Contingency Stock Planner
Use this worksheet when a supplier is late, unstable, being replaced, or sharing volume with a backup source. It helps decide how much safety stock is justified, when to release it, and when inventory risk is worse than supplier risk.
When to use it
- Lead time is unstable: actual shipment dates no longer match supplier promises.
- Quality risk is rising: replacement, rework or hidden defects may reduce usable stock.
- Volume is moving: orders are being split or transferred between old and new suppliers.
- Demand cannot stop: stockout cost is higher than temporary holding cost.
- Exit is possible: the current supplier may lose orders but still controls tooling, claims or documents.
Inputs to collect
| Input | What to record |
|---|---|
| Daily/weekly usage | Average demand, peak demand and committed customer orders. |
| Real lead time | Best, normal and worst recent delivery days, not only quoted lead time. |
| Usable-yield risk | Expected defect, shortage, damage or rework percentage. |
| Supplier recovery signal | Improving, unstable, worsening, or replacement in progress. |
Planner table
| Planning line | Simple formula or rule | Decision signal |
|---|---|---|
| Base cycle stock | Average demand × normal replenishment lead time. | Covers the normal order cycle only. |
| Delay buffer | Average demand × (worst recent lead time − normal lead time). | Add when supplier schedule evidence is weak. |
| Quality buffer | Base cycle stock × expected unusable percentage. | Add when inspection, rework or claim records are worsening. |
| Transfer buffer | One pilot-order window of demand for the SKU being moved. | Add before ramping a replacement or backup supplier. |
| Maximum buffer cap | Set a fixed date or quantity where holding cost, aging or specification-change risk becomes unacceptable. | Prevents “just in case” inventory from becoming a hidden loss. |
Release rules
- Hold contingency stock only for SKUs with verified demand or high stockout impact.
- Release buffer stock first to protect committed customers, not speculative volume.
- Recalculate after every shipment, arrival discrepancy report or supplier corrective-action milestone.
- Reduce the buffer only after two clean replenishment cycles or a successful replacement-supplier ramp-up.
- Stop buying extra buffer if the specification may change, customer demand is unconfirmed, or storage/aging risk is rising.
Decision outputs
| Evidence pattern | Action |
|---|---|
| Supplier late once, recovery evidence strong. | Use a short delay buffer and review after the next shipment. |
| Repeated late shipments and weak communication. | Increase delay buffer, activate backup supplier and prepare volume-transfer controls. |
| Quality defects reduce usable stock. | Add quality buffer and link each extra unit to corrective-action evidence. |
| Replacement supplier is piloting volume. | Keep transfer buffer until post-arrival review proves stable quality and documents. |
Do not build buffer when
- Demand is only a forecast with no customer commitment.
- The product may be redesigned, relabeled or certified under a new version.
- Warehouse conditions may damage the goods before use.
- The supplier risk should be solved by replacement, not hidden by inventory.
- Cash is better protected through split orders, payment controls or claim settlement.