Inventory Planning for a Store Chain: From the Season Budget to Each Store's Order

Replenishment answers what to order tomorrow. Inventory planning answers an earlier question: how much stock the chain should own this season, and in which stores. Get the plan wrong and no reorder rule saves it: the money is already committed, and the gap shows up months later as empty shelves or a bigger Sale.

1. What a wrong plan costs

Listed retailers report the result every year. In the year to January 2025, delays in the Suez Canal stretched NEXT's delivery times by about 17 days, so it placed orders two weeks earlier; full-price sales grew, but stock grew about twice as fast, surplus stock rose by 15%, and the extra markdown cost it 0.8 points of retail margin¹. Primark's parent reported higher inventory after softer sales in the second half of its 2025 year²: once the buy is committed, a weaker season turns straight into stock and tied-up cash.

Across the whole European textile market, the studies the European Environment Agency reviewed found on average about a fifth of products went unsold, and an estimated 4 to 9% of all textiles put on the market are destroyed before use; the agency names better forecasting and inventory management as the way to reduce it³.

2. Plan stock as a share of sales

The retailers that report it well keep one ratio in view: stock against sales. H&M states its stock as a share of rolling twelve-month sales⁴, Inditex reports inventory next to sales growth⁵, and Pepco reports stock days⁶. Read side by side, they show the plan working when stock grows slower than sales:

The right ratio depends on the category. In US retail data for August 2026, clothing stores held about two months of sales in stock and food stores less than one⁷:

So a chain that sells both needs a target per category, not one for the business. The stock turnover guide shows how to compute the same ratio from your own data.

3. The open-to-buy budget

Open to buy turns the ratio into a spending limit for a period. Start from the sales you plan, add the stock you want to end the period with and the markdowns you expect, then subtract the stock you start with and what is already on order. What remains is what buyers may still commit:

Two things make the budget honest. The closing stock comes from the target ratio, not from last year's habit. And part of it is held back on purpose: NEXT raised its stockholding by a further 6% in its latest year as protection against supply delays, a sized decision rather than an accident⁸.

4. From the chain to each store

A plan that holds for the chain rarely holds for each store. The further down a plan goes, from the chain to a category to one product in one store, the smaller and noisier the numbers, and the less any forecast can say:

So set the budget at chain and category level, and allocate to stores in stages: a first delivery sized from each store's own sales, and a reserve held back for whichever stores sell faster. Inditex's model of buying within the season from nearby suppliers is the same idea at a larger scale⁵. Moving stock that landed in the wrong store is covered in the guide to stock transfers, and each store's order in the reorder point and safety stock guides.

5. Review the plan every week

A season plan is a forecast, and it starts going wrong in the first week. Read three things each week: sell-through against plan by category and store, stock growing faster than sales, and products that have stopped selling. The sell-through guide shows the first; the dead-stock guide the last.

Even a well-run chain misses. NEXT's end-of-season Sale in January 2026 held more stock than it had expected, up 5% on the year before; better clearance than forecast covered the cost⁹. The point of weekly review is to see that gap in October, while stock can still be moved or reorders cut, rather than in the Sale.

A small chain reads the same signal in its own data. At the start of October 2026, Tuzeffy's four candy stores in Romania and their warehouse held more than six months of sales in stock at cost, and the two Brașov stores sat at opposite ends: Pralio held far more chocolate than it sold, while Yammy Way Brașov was selling through its pick-and-mix in under a month. A month later the chain held 10% less stock at cost, while its stores sold 27% more:

The Yammy Way and Pralio success story has the store-by-store reading and the options marql gave each store.

6. Limitations

The retailer figures are what each company chose to report, for years that end in different months, and mostly from fashion, where planning matters most. The category ratios come from US data; we found no comparable UK or EU series. The open-to-buy example is an illustration, not a benchmark.

How marql supports the plan

marql reads sales and stock for every product in every store from the POS and ERP a chain already uses. It shows each product's days of supply per store, lists stock that has stopped selling, and proposes store orders and transfers between stores as drafts that a person accepts or dismisses. Those are the weekly signals of section 5, read store by store rather than for the chain as a whole.