Optimizing Inventory Management: Turnover, Overstock and Locked-Up Cash

Quick answer. Optimizing inventory frees up cash without causing stockouts. First measure the turnover ratio (cost of goods sold / average inventory) and days inventory outstanding (average inventory / COGS × 365), then hunt down overstock and dead stock. Under French GAAP, inventory is valued at weighted-average cost or FIFO — LIFO is not allowed.

We regularly meet with business leaders facing a straightforward yet strategic question: why does my profit and loss account show profit, but my cash position is shrinking? The answer often lies in inventory management. Poorly managed stock equals locked-up cash—resources that are not working for your business.

As a chartered accountant and statutory auditor, we recently assisted an SME in the wholesale distribution sector in reducing its average inventory by 35 % over twelve months. The result: 180,000 € in freed-up cash, with no decline in turnover or sales disruption. This optimization rests on rigorous measurement and a shared diagnosis with operational teams.

This guide walks you through proven methods for managing inventory, interpreting turnover ratios and taking the right decisions to transform your stock into a financial asset.

Stock is a component of working capital requirement (WCR). The more money you tie up in inventory, the less you have available to fund growth, pay suppliers or invest. Conversely, strong inventory turnover releases cash organically.

Here's the mechanism: you purchase goods for €100. That money remains locked up until you sell the goods and collect from the customer. The longer the goods sit on the shelf, the longer the holding period, the more cash is tied up.

By optimizing your cash conversion cycle, notably by accelerating inventory turnover, you improve cash flow without changing your business strategy. This is especially critical during growth phases, when WCR financing can become a constraint.

Two key metrics gauge how fast inventory moves:

Inventory turnover ratio: turnover = cost of goods sold (COGS) / average inventory. This metric shows how many times you replace your stock over a period (typically one year). A turnover of 5 means you sell through your entire inventory 5 times per year.

Days inventory outstanding (DIO): DIO = average inventory / COGS × 365. This indicates the average number of days a product sits in inventory before sale. A DIO of 73 days means stock remains in warehouse an average of two and a half months before it sells.

The relationship between these two metrics is straightforward: higher turnover means shorter DIO. Stock turning 5 times per year corresponds to a DIO of roughly 73 days (365 ÷ 5).

To compute average inventory: add opening and closing inventory for the period, then divide by 2. A more refined approach, if monthly data is available, is to calculate the arithmetic average of all monthly balances.

No single turnover rate applies universally across all sectors. A retail multi-category store will target much faster turnover than a specialist hardware shop or a made-to-order carpentry firm. Here is a sector benchmark:

Good turnover means inventory refreshes regularly, cash flows and obsolescence risk is controlled. Poor turnover signals dormant stock, demand lower than forecast or a purchasing planning error.

Overstock is purchasing in excess of demand. Dormant stock is merchandise that no longer sells. Both tie up cash unnecessarily.

Red flags:

• Turnover below sector norms for more than two consecutive quarters
• Inventory rising steadily while turnover stagnates
• Stock items with zero outflow over 12 months
• Accumulation of small quantities of obsolete or discontinued products
• Stock-to-monthly-turnover ratio > 3 (rule of thumb: inventory should not exceed 2.5 to 3 times monthly revenue)

To identify overstock precisely, analyze outflow velocity by item: calculate turnover per item = annual outflows / average item inventory. Items with zero movement (turnover < 0.5) are candidates for markdown or elimination.

The central challenge: free up cash without losing sales. Here are the structural levers:

1. Segment inventory by turnover speed (ABC method: fast-moving, medium, slow). Increase replenishment frequency for fast movers; reduce buffers for slow items.

2. Improve demand forecasting using sales history and seasonal adjustment. Systematic forecast gaps = recurring overstock or stockouts.

3. Negotiate shorter lead times with suppliers. Shorter lead times allow proportional reductions in safety stock.

4. Set right-sized safety stock: do not aim for zero; maintain a minimum that prevents stockouts without waste. Formula: safety stock = safety factor × demand standard deviation × lead time.

5. Implement just-in-time (JIT) inventory for bulky or high-value items. Orders arrive at the moment of need, not before.

6. Launch controlled promotions or markdowns to clear overstock without gutting margins. Slow-moving goods at −50% generate cash better than the same goods at full price.

7. Test online or multichannel sales: an item with poor in-store sales may find buyers online. Splitting stock across channels boosts overall turnover.

8. Align purchasing with the commercial calendar (seasonal sales periods) and the company's cash cycle.

Working capital requirement comprises three elements: customer receivables, inventory and supplier payables. We detail this in our comprehensive guide to financial management and WCR.

Simplified formula: WCR = inventory + receivables − payables.

Rising inventory = rising WCR = cash consumption. Conversely, reducing inventory by €100,000 frees €100,000 in cash (all else being equal).

In parallel, we recommend active management of the full cycle: optimize customer payment terms (DSO), negotiate supplier terms (DPO) and reduce inventory days (DIO). Sound overall cash cycle management can unlock substantial cash.

For example, a €5 million revenue distribution SME with €600,000 WCR (43 days of revenue) could recover €150,000 in cash by tightening its cycle by 11 days (from 43 to 32 days). That is free cash with no additional growth.

As a chartered accountant, we must also address the accounting treatment of inventory, which directly impacts your profit and tax bill.

Inventory valuation method at exit: French accounting standards recognize two approaches:

• Weighted average cost (WAC): exit value is the weighted average of purchase cost. It is the most common and stable method.
• FIFO (First In, First Out): we assume that the oldest purchased items leave first. During periods of rising prices, this results in lower cost of goods sold and higher reported profit.

Critical: the LIFO (Last In, First Out) method is forbidden in French statutory accounts (it is permitted only in consolidated accounts under IFRS).

Inventory impairment: under the French Chart of Accounts (article 214-22) and ANC regulation 2014-03, inventory is valued at the lower of acquisition (or production) cost and net realizable value (NRV). If the market has fallen or the product becomes obsolete, you must record an impairment.

Example: you purchased goods at €100 ex-VAT. Today they sell for €75 ex-VAT on the market, and you estimate disposal costs at €10. NRV is €65. You must impair the inventory by €100 − €65 = €35 and record a provision for impairment (account 391 or 392). This impairment is tax-deductible if justified (obsolescence, documented market decline).

Caution: obsolete or unsaleable stock must be fully impaired regardless of how long it has been held. There is no legal threshold beyond which stock automatically becomes impairment-proof.

Retail#

Turnover should be rapid (6–15 per year) to minimize shrinkage (theft, wear, obsolescence). The key issue is seasonal management (Christmas, clearance sales, back-to-school) and end-of-season liquidation. Out-of-season fashion items must be marked down promptly.

Manufacturing and subcontracting#

Inventory is less a turnover problem than an issue of production lead time and on-time delivery to customers. The ideal is lean flow: raw materials arrive when needed, finished goods ship immediately after production. Longer production lead times = higher work-in-progress stock.

Food service and catering#

Turnover is very rapid (10–30 per year) because perishability is the dominant factor. A restaurant cannot store ingredients for two months. The challenge is not turnover per se but waste minimization and compliance with food safety standards. Financial management in the food service sector requires very precise demand forecasting.

Interest rates and WCR financing cost: if your WCR is financed via overdraft or short-term credit, monitor rates. Reducing locked-up inventory can drive meaningful interest savings.

Bank covenants: if you have a term loan (medium or long-term credit), the contract may impose thresholds on liquidity ratios or debt ratios. WCR deterioration can trigger a covenant breach, allowing the bank to demand accelerated repayment. We detail this risk in our guide to financial ratios and covenants.

Inflation and revaluation: if purchase prices rise, WAC smooths the impact to cost of goods sold, whereas FIFO leads to lower initial selling prices (tight margins). Prefer WAC in inflationary periods.

Traceability and count verification (internal controls): as statutory auditor, we must validate the reliability of your physical inventory. Stock recorded on books far from reality = audit risk with qualifications. Count at least once per year (mandatory before year-end closing).

Optimizing inventory management means actively steering rather than passively accepting fluctuations. Too often we see business leaders manage stock by inertia: "We have always bought 100 units of this product each month." Yet your market may have shifted. Your customers may demand shorter lead times. Your sector may have accelerated.

Best practice involves:

1. Measuring turnover ratios by product category (ABC method).
2. Systematically comparing your results to sector benchmarks.
3. Adjusting purchases based on demand forecasts, not residual stock.
4. Collaborating with operational teams (sales, logistics) to identify real rotation bottlenecks.
5. Validating the accounting impact: impairment if needed, review of valuation method if it no longer reflects reality.

Recently, a director of an electronics SME approached us because cash was drying up despite growing turnover. We analyzed inventory by item and found that 40 % of inventory value consisted of items sold fewer than 3 times per year. After gradual reduction and controlled liquidation, the company freed €220,000 over four months and improved turnover by +35 %. Its 25 % corporate tax rate did not change, but net margin improved by 2 percentage points thanks to interest savings and freed cash.

Hayot Expertise advice: manage inventory like a financial asset, not a logistics burden. Every euro locked in dormant stock is a euro not working for you. As a chartered accountant and statutory auditor, we assist you in detailed ratio analysis, validation of your inventory accounting and identification of concrete optimization levers. Rigorous inventory management translates directly to improvement in gross margin and net profitability.