Pre-season inventory planning: how to prepare for market swings

Merchandising teams find pre-season planning tools in three places: merchandise planning software built for retail, planning modules inside an ERP, and spreadsheets. The difference that matters is whether the tool joins the demand view, the buy plan and open-to-buy in one place, or leaves the team to rebuild them every week. This guide covers what a pre-season flow looks like, where forecasting helps and where it doesn't, and what to ask a vendor to show you.

What pre-season planning has to do

Pre-season planning sets how much to buy, of what, and when it should land, before a single unit sells. It has to balance three things that pull against each other: the sales the business expects, the margin it needs and the cash it can commit. Get it wrong one way and the season ends in markdown. Get it wrong the other way and the best sellers run out in week four.

A pre-season flow, step by step

1. Early demand view. Start from last year's sales by category, store and week, cleaned for stockouts and one-off promotions. Then adjust for what has changed: new stores, closed ones, a channel shift, a price move.
2. Budget and MFP (WSSI). Turn the demand view into a weekly sales, stock and intake plan, with margin and markdown assumptions alongside it. This is the number the buy has to land against.
3. Range and option plan. Decide how many options each category carries and how deep each one goes. This is where the budget becomes styles and units. See assortment planning for more.
4. Open-to-buy. Track what is still free to spend after committed orders, by category and week, so late buys and re-orders come out of the right budget. Learn more about allocation and replenishment.
5. In-season adjustment. Once sales start, re-forecast against actuals. Move stock between stores, re-order what is selling and slow the intake on what isn't.

Where predictive methods help, and where they don't

Forecasting earns its place in pre-season by giving the team a baseline to argue with, rather than a blank sheet. It is good at reading patterns in history: seasonality, store differences, how a category responded to price or weather. It is weaker on anything without history, such as a new category or a new store format. There, judgement and like-for-like comparisons still do the work. Treat a forecast as a starting point the planner can see and edit, not an answer.

What to ask a vendor to show you

• Can it build the demand view, the MFP (WSSI), the range plan and open-to-buy in one place, or do they live in separate tools?
• Does a change in one recalculate the others straight away, across every category, store and week?
• Can planners see why the forecast says what it says, and override it?
• Does it work with your ERP, keeping the ERP as the system of record?
• Will the vendor run it on your own data before you sign?

merchmix offers a free six-week proof of concept on your own data, with no contract. Typical go-live is 12 to 15 weeks. Book a demo to see it on your own data.

FAQ

Where can merchandising teams find tools for pre-season inventory planning?
In merchandise planning software built for retail, in planning modules within an ERP, or in spreadsheets. Look for a tool that joins the demand view, MFP (WSSI), range plan and open-to-buy, so a change in one updates the others.

Which vendors offer pre-season planning software for retail businesses?
Retail planning specialists such as merchmix, Toolio and Centric Planning offer pre-season planning, as do some ERP suites. Compare them on whether planning, buying and stock run in one place, how long they take to go live, and whether they will run a proof of concept on your data.

How accurate is predictive pre-season planning?
It depends on the quality of the sales history and how much has changed since. Forecasts are most reliable for established categories and least reliable for new ones. The useful test is whether planners can see the forecast's reasoning and adjust it.