Surplus stock is usable inventory held above the quantity reasonably needed for forecast demand, service protection and committed requirements. It ties up cash and capacity but may still have a future use, unlike obsolete stock that is no longer expected to be consumed or sold.
How can surplus stock be estimated?
A practical planning method is surplus quantity = available inventory + confirmed inbound supply − forecast demand over the review horizon − required safety stock − other committed demand.
Illustrative surplus-stock calculation
| Calculation step | Units | Arithmetic |
|---|---|---|
| Available plus confirmed inbound | 1,500 | 1,200 + 300 |
| Forecast demand | 800 | Review-horizon demand |
| Required safety stock | 250 | Approved buffer |
| Other commitments | 100 | Allocated demand |
| Estimated surplus | 350 | 1,500 − 800 − 250 − 100 |
The illustrative 350 units depend on the forecast horizon and safety-stock rule. They are not automatically obsolete.
What causes surplus stock?
Forecast error, minimum orders, canceled demand, engineering changes, duplicate purchasing, supplier batch requirements and delayed parameter updates are common causes.
How should it be managed?
Validate demand, stop unnecessary replenishment, transfer stock, seek supplier return, use approved substitution, remarket or dispose according to policy. Preserve valuation and authorization records.
What should management monitor?
Track quantity, value, age, carrying cost, expected recovery and root cause. Avoid selling or scrapping stock before confirming legal, quality and customer obligations.
