WSSI (Weekly Sales, Stock and Intake)
The WSSI is a weekly merchandise planning worksheet that reconciles sales, stock, and intake against plan — the in-season control tool behind open-to-buy decisions.
The WSSI (Weekly Sales, Stock and Intake) is a weekly merchandise planning worksheet that lays out planned and actual sales, stock levels, and intake (receipts) side by side, week by week, for a department or category — so the planner can see whether the season is trading to plan and how much open-to-buy remains. It is the standard in-season control document in UK and European merchandise planning, and the same structure appears in US planning under names like the weekly sales and stock plan.
What the WSSI contains
Each week's row reconciles four things:
- Sales — planned vs actual units or value, with markdown spend broken out.
- Stock — the closing stock position the week's trading produces.
- Intake — receipts landing that week, planned and committed.
- Forward cover — closing stock expressed as weeks of supply against forward sales.
The arithmetic is a rolling inventory bridge: opening stock, minus sales and markdowns, plus intake, equals closing stock. Because every week's closing stock is the next week's opening stock, one bad week visibly reprices the whole rest of the season — which is exactly the point.
How planners use it
The WSSI is a trading tool, not a reporting artifact. In a weekly trade meeting it answers three questions in order: are we selling to plan, is stock where the plan said it would be, and what does that do to the intake we have committed? When sales run behind, forward cover builds and the WSSI shows precisely how much intake needs to move, cancel, or re-phase to protect the closing stock target. When sales run ahead, it shows how much open-to-buy has been earned and how quickly it must be spent to hold cover.
Reforecasting happens directly in the sheet: the planner overwrites forward sales weeks with the new expectation, and the stock and intake consequences cascade automatically.
WSSI vs OTB
Open-to-buy is a number the WSSI produces, not a separate document. The OTB calculation tells you how much buying budget remains for a period; the WSSI is the weekly machinery that keeps that number honest as actual sales replace planned ones. A monthly OTB reviewed without a weekly WSSI behind it is four weeks late to every problem.
A spreadsheet WSSI works for one department. The structure breaks when a planning team runs it across many departments and channels, because each sheet's reforecast has to be re-keyed into the merchandise financial plan by hand. If you want the classic single-department structure to start from, our sister site retail-plan.com has a free WSSI template.
RetailNorthstar runs the WSSI logic on a shared data model: actuals flow in weekly, reforecasts cascade to OTB and the merchandise financial plan automatically, and forward cover is visible by channel without re-keying. See how RetailNorthstar handles in-season planning →