Retail planning glossary

Plain-English definitions of the terms behind retail and apparel planning — each cross-linked to a calculator or guide.

Open-to-Buy (OTB)

Open-to-buy (OTB) is the amount of inventory, in retail dollars, a buyer can still receive in a period without exceeding the plan. It is calculated as planned end-of-month stock + planned sales + planned markdowns − beginning stock − merchandise on order.

Sell-Through Rate

Sell-through rate is the share of received units that have sold over a period — units sold ÷ units received × 100. It signals how fast a style is selling and whether it needs a reorder or a markdown.

Gross Margin Return on Inventory (GMROI)

GMROI (gross margin return on inventory) is the gross-margin dollars earned per dollar of average inventory at cost — gross margin ($) ÷ average inventory at cost. A result above 1.0× means margin exceeds the inventory investment.

Weekly Sales, Stock & Intake (WSSI)

A WSSI (Weekly Sales, Stock & Intake) is a weekly retail plan that tracks the flow of stock through a season. Its core identity is closing stock = opening stock + intake − sales, with each week’s closing becoming the next week’s opening.

Time & Action Calendar (T&A)

A time & action (T&A) calendar maps every apparel production milestone backward from the in-store date, with an owner and a lead time on each step and a buffer at the end — so a slip surfaces the moment a milestone moves.

Work in Progress (WIP)

In apparel, work-in-progress (WIP) is the set of orders currently in production — between the placed PO and the received delivery. Tracking WIP by style and milestone shows where each order sits and whether it is on track for the in-store date.