Knowledge · Inventory strategy
High inventory secures availability but ties up capital and space. Low inventory is capital-efficient but raises the shortage risk. Both extremes have their place – the question is never "high or low" but "how much for which item". This article contrasts the pros and cons objectively and shows how to calculate the right balance per item.
Yes. High inventory buffers demand peaks and delivery delays, securing high availability. It allows larger, cheaper order quantities (volume discounts, fewer orders) and protects against raw-material price rises. In volatile supply chains, stock can be a deliberate risk buffer.
These advantages are real – but they carry a price that is often underestimated, because tied-up capital does not appear in the P&L like a direct cost item.
High stock ties up capital and causes cost of capital of typically 6–12 % p.a., plus warehousing, handling, insurance and obsolescence costs and the risk of write-downs. High stock also hides process problems: whoever buffers enough won't notice for a long time that forecasting or suppliers are unreliable.
Low stock frees capital, lowers warehousing costs and makes process errors visible immediately – a core idea of lean production. The downside: the buffer against demand and supply variability shrinks. Without a reliable forecast the shortage risk rises, and shortages are expensive – through expediting, downtime or lost orders.
Low stock works well when demand is forecast precisely and replenishment is reliable. That is why forecast quality and low inventory belong together.
The answer is item-dependent. Easily forecastable, steady items (classic A/X items) tolerate low stock because their demand barely varies. Sporadic or highly variable items need relatively more buffer – or a different sourcing strategy. Flat coverage across the whole range almost inevitably over-stocks some and under-stocks others.
The optimal balance is therefore not a single value but a per-item calculation: expected demand plus a safety stock that covers exactly the individual spread up to the target service level.
Whether stock is too high or too low is not a gut call but a function of demand spread. Our inventory-optimisation article and the safety-stock calculator show how to calculate the balance per item.
Yes: high inventory secures availability during demand peaks and delivery delays, enables cheaper bulk orders and protects against price rises. But these advantages face tied-up capital, warehousing and obsolescence costs, and the risk that stock hides process problems. Higher stock is sensible mainly for highly variable or hard-to-forecast demand.
Low inventory frees capital, lowers warehousing costs and exposes process weaknesses. Its downside is a higher shortage risk when demand or lead times fluctuate. Low stock is viable when demand is forecast precisely and replenishment is reliable.
The optimal balance is item-dependent and follows from a calculation: expected demand over the lead time plus a safety stock covering the individual demand spread up to the desired service level. Instead of one flat coverage for the whole range, each item gets the stock its demand actually requires.