3.1Role and cost of inventory
The essentials in 30 seconds
- Stock = buffer with precise functions: service, safety, cycle, anticipation — no function, no justification.
- Holding costs 15 to 30% per year (capital + warehousing + depreciation): a massive cost because scattered and invisible.
- Managing = balancing carrying / ordering / stockout: neither "just in case" nor dogmatic zero stock.
Running mini-case — Nadia discovers what her stock costs
Nadia, a buyer in an agri-food SME importing raw materials in Algiers, defends her high stock: "you never know with port delays". Costing carrying at 20%, she discovers her €30,000 of dead stock costs €6,000 every year without protecting a single sale. This case runs through the lesson, the diagram, the script and the 48h challenge — and continues in 3.2, 3.3, 3.4 and 3.5.
This same case runs through the lesson, the diagram, the script and the 48h challenge — and continues in 3.2, 3.3, 3.4 and 3.5.
1. Stock functions: a buffer with precise roles
Stock is a buffer that decouples incompatible rhythms. Service stock: serve immediately without waiting for replenishment. Safety stock: absorb demand and lead-time variability. Cycle stock: benefit from economic lots and MOQs. Anticipation stock: build or buy ahead of a seasonal peak. Speculative stock: buy ahead of an announced price rise.
Every pocket of stock fills — or should fill — one of these functions. Stock with no identifiable function has no reason to exist: it is a "just in case" that ties up cash with no real protection.
The real question is therefore never "do we need stock?" but "what function does this stock serve, and at what price?" — function by function, item by item.
2. The three costs in tension
Carrying cost: tied-up cash (missing working capital or interest), warehousing (space, energy, handling, insurance) and shrinkage (breakage, theft, expiry, obsolescence). Typical total: 15 to 30 % of stock value per year — invisible because scattered, but massive: 100 000 € of stock = 15 000 to 30 000 € per year.
Ordering cost: fixed cost of each order (admin, transport, receiving). Ordering very often in small quantities multiplies it. Stockout cost: lost sales, stopped production, lost customers (sometimes for good), emergency fixes at full price — the most devastating and most underestimated.
Managing stock means optimising the carrying / ordering / stockout trade-off: enough to avoid stockouts, little enough to contain carrying, grouped enough to absorb ordering.
3. Right-sized stock, neither bloated nor dogmatic
Neither bloated "just in case" stock nor dogmatic zero stock: right-sized stock is the level with the lowest total cost. Removing stock without making the chain reliable removes the shock absorber while keeping the potholes — every disruption becomes a stockout.
"Zero stock" has been misunderstood: in just-in-time, lower stock is the result of a reliable chain (close and dependable suppliers, frequent deliveries, controlled quality), not a decreed decision.
This level 3 equips that living adjustment: valuation methods, reorder point, safety stock, ABC, turnover and accuracy — for right-sized stock per item, recalculated when parameters move.
🔎 Concrete example — The stock that costs more than its value
An SME holds 120 000 € of average stock including 30 000 € of dead stock with no function. At a 20 % carrying rate, holding costs 24 000 €/year — including 6 000 € for the dead stock alone.
Reading: keeping dead stock "just in case" costs 6 000 € every year without protecting a single sale.
Action: mark down, return or donate: recovered cash and freed space beat a balance-sheet value.
Section vocabulary
- Inventory functions
- Service (serve without waiting), safety (absorb variability), cycle (lots and MOQ), anticipation (seasonality), speculation (ahead of a price rise).
Simple example: Nadia classifies her pockets: packaging as cycle (supplier MOQ), sensitive material as safety (port delays).
What it is not: keeping a "just in case" without being able to name its function.
Reflex: for each family, write its function in one word — otherwise plan its liquidation.
- Carrying cost
- Annual holding cost: tied-up cash + warehousing + depreciation (breakage, theft, expiry, obsolescence); 15 to 30% of value per year.
Simple example: Nadia applies 20% to her €120,000: €24,000 per year of holding.
What it is not: looking only at the balance-sheet value without costing annual holding.
Reflex: value average stock × 20% to make the cost visible.
- Ordering cost
- Fixed cost of each order (admin, transport, receiving); multiplied if you order too often in too small quantities.
Simple example: Nadia groups her small spice orders to spread the transport cost.
What it is not: multiplying urgent micro-orders without grouping.
Reflex: count the number of orders per family before adding one.
- Stockout cost
- Cost of a stockout: lost sales, stopped production, lost customers, emergency fixes at full price — the highest and most underestimated.
Simple example: Nadia costs a material stockout: line stopped and customer delivered late.
What it is not: ignoring it because it has no dedicated accounting line.
Reflex: log each stockout with its cause and actual observed cost.
- Obsolescence
- Loss of value of stock that has become unsellable (fashion, technology, expiry); the silent depreciation of sleeping stock.
Simple example: Nadia clears a batch close to its expiry date before it becomes unsellable.
What it is not: letting a perishable batch sleep "just in case" until expiry.
Reflex: list batches with no movement each month and decide their fate.
In practice — Quantify what your stock really costs
- Estimate the value of your average stock (or a representative family) at purchase price.
- Apply a 20 % annual carrying rate (cash + warehousing + shrinkage): that is the yearly holding cost.
- Identify the function of each large pocket: service? safety? imposed lot (MOQ)? seasonality? none?
- Spot function-less stock (dead, obsolete, just in case): quantify it — your first savings pool.
Ready-to-say script — defending destocking to the manager (1 min)
"Our dead stock is worth €30,000 on the balance sheet but costs us €6,000 every year without protecting a single sale. I propose clearing or returning it: we recover cash, free up space, and keep the stock that has a real function."
Figure + function + proposal: the trio that gets destocking accepted.
Copy-paste template — function / cost card per pocket
FAMILY / ITEM: _______________
AVERAGE STOCK VALUE: _______________
FUNCTION (service / safety / cycle / anticipation / none): _______________
CARRYING COST (value x 20%): _______________
DECISION (keep / reduce / liquidate): _______________VSE / small budget
No software needed: a spreadsheet with value per family and 20% carrying is enough to reveal the first saving.
Algeria SME
Variable import lead times via Algiers: separate legitimate safety (covering the port) from "just in case" dead stock that protects nothing.
Perishable agri-food
Expiry makes carrying costlier: date each batch and clear before the deadline rather than throwing away after.
Distribution / trading
Sort by family sold: dead stock of a discontinued item is cleared fast, the space serves fast movers.
✓ Best practices
- Quantify carrying at 20 % by default: this rate finally makes stock comparable to other costs.
- Question every pocket: with no clear function, plan its clearance.
- Do not confuse balance-sheet value with realisable value: dead stock valued at cost still costs every year.
✗ Common pitfalls
- Targeting zero stock as dogma without making suppliers and lead times reliable: you manufacture stockouts.
- Keeping dead stock "just in case" indefinitely: 20 % per year, every year.
- Ignoring stockout cost (image, lost customer) because it has no accounting line.
Key takeaways
- Stock is a BUFFER with precise functions: service, safety, cycle, anticipation — no function, no justification.
- Holding stock costs 15 to 30 % of its value per year (tied-up cash + warehousing + shrinkage) — massive and invisible.
- Three costs in tension: carrying (too much), ordering (too frequent), stockout (too little) — managing means optimising the trade-off.
- Neither "you never know" nor dogmatic zero stock: RIGHT-SIZED stock, function by function, item by item.
48h Challenge — apply tomorrow
Like Nadia: take 1 stock family, note its function and cost its carrying at 20%. If it has no function, propose its fate (clear, return, donate). 20 minutes is enough.
- I can name the 5 functions and the 3 costs without hesitation.
- I costed one family's carrying at 20%.
- I spotted a stock with no function and proposed its fate.
Frequently asked questions
Is zero stock not the ideal?
No: it is a slogan. The ideal is stock at minimum total cost, rarely zero. In just-in-time, lower stock results from a reliable chain (dependable, close suppliers delivering often; controlled quality), not an isolated decision. Removing the buffer without improving reliability creates stockouts whose cost exceeds the saving.
My accountant sees stock as an asset, my consultant as a hidden liability: who is right?
Both. On the balance sheet it is an asset (goods for sale). Economically it has eaten cash (working-capital need), costs 15-30 % per year in scattered form and may be overstated if dead stock stays valued at cost. A company can be profitable and die from cash tied up in bloated stock.
Roughly how much does holding stock cost per year?