Inventory how-to

How to handle one big order that skews your forecast

One large order can make your average daily sales look much higher than normal, which pushes forecasts and order quantities up.

Short answer: One large order can make your average daily sales look much higher than normal, which pushes forecasts and order quantities up. The fix is to either exclude that order from the sales history used for forecasting, or manually cap the quantity when you place the purchase order.

Why this happens

Forecasting tools, including SteadyShelf, usually look at a recent sales window (by default 28 days) to work out daily sales per variant. If one order in that window was ten or twenty times your normal order size, it drags the average up sharply. The result is a reorder point and order quantity that assume this kind of order happens often, when it was really a one-off.

Spot it before it costs you

Check any SKU with a sudden jump in suggested order quantity against your recent order history. If you see one wholesale order, a gift set bulk buy, or a single customer buying out your stock, that is likely the cause. This is more common for SKUs with naturally low daily sales, where one order has an outsized effect on the average.

How to correct it

If the tool lets you adjust or exclude specific order lines from the sales window, do that first. If not, manually reduce the suggested order quantity back down to what matches your normal daily sales, and treat the big order as a separate note rather than a new baseline. Keep an eye on the next few weeks of sales to see if the higher pace continues or if it was genuinely a one-off.

Step by step

  1. Identify the SKU where the suggested order quantity looks unusually high.
  2. Check recent order history for that SKU to find the large order.
  3. Confirm it was a one-off: a wholesale buyer, a bulk gift order, or similar, not a new sales trend.
  4. If possible, exclude that order from the sales data used to calculate the forecast.
  5. If you cannot exclude it, manually lower the order quantity to match normal daily sales before approving the purchase order.
  6. Watch sales over the next couple of weeks to confirm the normal rate has resumed.
  7. Only raise your reorder quantity permanently if the higher sales pace continues.

Worked example

Say a SKU normally sells 2 units a day, but a wholesale customer bought 100 units in one order last week. Over the 28-day window, that pushes average daily sales from 2 to roughly 5.6 units a day. If lead time is 14 days and safety days are 7, the reorder point would jump from 42 units (2 x 21) to about 118 units (5.6 x 21). Recognizing the 100-unit order as a one-off and removing it from the calculation brings the reorder point back down to the realistic 42 units.

How SteadyShelf helps

SteadyShelf calculates forecasts from your sales window automatically, so a single large order can temporarily skew the suggested quantities. You can review and manually adjust any suggested order quantity before approving the purchase order, which is the practical way to correct for a one-off spike. It does not currently let you flag individual orders as outliers to exclude from the forecast window itself.

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

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FAQ

Will the skewed forecast fix itself over time?

Yes, once the large order rolls out of the sales window, the average daily sales figure will drop back to normal. With a 28-day window, that happens within about four weeks, so the effect is temporary even if you do nothing.

Should I remove the order from my store records entirely?

No, keep the order in your records for accounting and customer history. The adjustment should only affect the quantity you choose to reorder, not your actual sales records.

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