How far in advance should retailers forecast seasonal demand?

Begin planning early enough to cover supplier production, transportation, receiving, and additional safety time. A retailer working with a six-month supplier lead time must start much earlier than one that can replenish within two weeks. Continue forecasting after the initial order to update marketing, allocation, and markdown decisions.

What is forecast bias in seasonal planning?

Forecast bias is a consistent tendency to forecast demand too high or too low. Optimistic forecasts contribute to excess inventory and markdowns, while conservative forecasts increase stockout and missed-sales risk. Review bias separately from average forecast error because overforecasting and underforecasting can otherwise cancel each other out.

Should every seasonal product have the same target service level?

No. Set the service level according to the product’s margin, stockout cost, post-season value, available substitutes, and reorder options. A core, high-margin product often warrants a higher availability target than a dated seasonal item with little value after the peak.

Which metrics should retailers review after the season?

Review forecast error and bias alongside commercial outcomes such as sell-through, gross margin, markdown rate, stock availability, end-of-season inventory, and cash tied up in stock. Statistical accuracy does not guarantee a strong purchasing result. Poor order timing, supplier constraints, or the wrong product mix can still weaken performance.

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