Inventory how-to

How to buy inventory for a new collection

For a new collection you have no sales history, so you cannot forecast from past demand.

Short answer: For a new collection you have no sales history, so you cannot forecast from past demand. Instead you set a starting order based on a sales guess, cap your risk with a small initial buy, and switch to normal forecasting once you have a few weeks of real sales data.

Start with a demand guess, not a forecast

Pick a comparable product or collection you already sell and use its early sales pace as a stand-in. If you have nothing comparable, estimate units per week per variant from your traffic plans, marketing push, and gut sense of the market. Write the number down so you can check it against reality later.

Buy small, buy often at first

Order enough stock to cover 3 to 5 weeks, not a full season. New collections are guesses, and guesses are wrong half the time. A smaller first order means a smaller mistake if sizes, colors, or the whole collection underperforms, and it lets you reorder the winners fast once real sales come in.

Split the buy across variants carefully

Do not split evenly across every size and color by default. Use whatever signal you have (wishlist adds, pre-order interest, past collections' size curves) to weight the order. If you have truly no signal, order a flatter spread but keep quantities low per variant so a wrong guess is cheap.

Watch the first few weeks closely

Check sell-through per variant at the end of week 1 and week 2. If a variant is selling much faster than guessed, reorder it immediately, accounting for the supplier's lead time. If something is not moving, do not reorder it and consider a markdown before you place a second collection-wide order.

Step by step

  1. Estimate weekly demand per variant using a comparable product or your best judgment.
  2. Set an initial order size covering 3 to 5 weeks of that estimated demand, not more.
  3. Weight quantities across sizes and colors using any signal you have, or keep it flat and low if you have none.
  4. Confirm supplier lead time and case pack minimums before finalizing quantities.
  5. Place the order and track actual sales per variant from day one.
  6. At week 2, compare actual sales to your guess and reorder fast-movers, accounting for lead time.
  7. Once you have about 4 weeks of sales data, switch that collection to normal reorder planning.

Worked example

A store is launching a new candle collection with 5 scents. Based on how a similar collection performed in its first month, the owner guesses 10 units per scent per week. They order 4 weeks of cover: 10 x 4 = 40 units per scent, 200 units total, split evenly since they have no other signal. By the end of week 2, one scent has sold 35 of its 40 units while the others have sold around 15 each. The owner reorders the fast scent immediately, using its supplier's 2-week lead time and a 3-day safety stock: reorder point = 5 units/day x (14 + 3) = 85, which it has already passed, so the order goes in now.

How SteadyShelf helps

SteadyShelf forecasts from a 28-day sales window, so it has nothing to work with for a brand-new collection until sales start coming in. Do the first buy manually as above, then once each variant has a few weeks of sales history, SteadyShelf can pick up forecasting and reorder dates for it automatically.

$29/month flat, unlimited products and suppliers, 30-day free trial. Run the numbers now with the free reorder point calculator.

SteadyShelf is launching on the Shopify App Store. Join early access to get the install link first.

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FAQ

Should I order the same quantity for every size in a new collection?

No, not if you have any sizing signal from past collections. Most apparel and footwear lines sell more in middle sizes than extremes. If you have no data at all, a flat spread is a reasonable fallback, but keep total quantities low so an uneven guess does not cost much.

When should I place a second, bigger order for the collection?

Once you have 3 to 4 weeks of actual sales per variant, you can calculate a real daily sales rate and use it to size a proper reorder, factoring in supplier lead time and how many days of cover you want. Avoid committing to a large second order before that data exists.

Let SteadyShelf do this math for every SKU

Order-by dates per supplier, seasonal forecasts and draft POs for your Shopify store. $29/month after a 30-day free trial.

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