How to Run a Monthly Demand and Inventory Review: A Demand Planning Process for Growing Brands

What Is a Monthly Demand and Inventory Review?

TL;DR A monthly demand and inventory review is the heartbeat of a strong demand planning process — and the sequence matters. Start with forecast vs. actual at the category level. Get more granular from there. Analyze what's driving performance, then reforecast. Dig into WOS and sell-through, check your inventory alerts, reconcile OTB, and then zoom out to gross margin and net sales. Run it in this order and every number has context. This post walks through the whole thing.

Demand Planning Process: How to Run a Monthly Demand and Inventory Review for Growing Brands

Here's a situation most scaling brand founders know well, (and it’s not part of a strategic demand planning process.). It's the first week of the month. Someone pulls a report. There's a quick scan of the numbers, a few items get flagged, and then everyone gets pulled back into the daily fire. That's not a monthly demand and inventory review. That's inventory anxiety dressed up as a process.

A monthly demand and inventory review is the heartbeat of a strong demand planning process. Each step builds on the one before it. By the time you reach the end, you're actively shaping what happens next. Done consistently, it's the most reliable way to improve inventory turnover, reduce stockouts, and stop buying decisions from being made on gut instinct three weeks too late.

At Boon, the monthly demand and inventory review sits at the core of the demand planning process we run for every client. It keeps forecasting grounded in current reality. As a result, open-to-buy planning stays connected to actual demand — not the demand someone predicted back in August. 

Here's exactly how to run it.

Step 1: Start Your Demand Planning Process With Forecast Accuracy

Every demand planning process starts in the same place: forecast versus actual demand at the category level. This gives you the summary you need to orient the rest of the review. But don't stop there.

Get detailed — subcategory, then SKU for anything with meaningful volume or notable variance. When you review at the detailed level, the summary stops being a mystery. For example, you're not staring at a +12% category variance wondering where it came from. You already know which items drove it and whether it's a signal worth acting on.

In addition, this detailed review covers your assortment analysis. Track forecast versus actuals at the subcategory and item level and you're already seeing which styles are resonating and which aren't.

Step 2: Analyze Demand Performance to Improve Forecast Accuracy

A demand planning process that only measures variance without asking why isn't doing its job.

For any category or item running ahead of forecast, dig into the cause. Channel shift? A campaign that outperformed? Organic demand that wasn't anticipated? Understanding what drove a top performer makes your next forecast sharper. As a result, you start building real patterns into your assumptions.

The same logic applies to underperformers. Below-forecast performance might signal a demand problem. It might instead signal an inventory problem. Those require very different responses — and the next step will help you tell the difference.

Step 2b: Reforecast Demand Based on Current Performance

With your performance analysis complete, reforecast demand for the rest of the season. Your updated forecast is the foundation for every decision that follows in this demand planning process. Get this right before moving on.

Step 3: Use WOS, Sales Velocity, and Sell-Through to Assess Inventory Health

Pull weeks of supply, sales velocity, and sell-through for all active items. Get granular!

Sales velocity tells you how quickly each item moves through its inventory. Strong velocity with low WOS means stockout risk. Weak velocity with high WOS means too many inventory dollars in the wrong place. Both situations need action.

Total sell-through shows how consistent demand has been over time. Consistently high sell-through signals a reliable performer worth deeper inventory investment. Erratic sell-through, means more scrutiny before you commit again.

One important carry-forward from Step 2: an item that underperformed its forecast might have simply run out of inventory before it had a chance to sell. WOS and velocity data help you tell the difference between "customers didn't want this" and "customers couldn't get this."

Step 4: Review Inventory Alerts to Prevent Stockouts and Overstock

Review inventory levels to determine where you have stockout or overstock risk.

Declining WOS signals stockout risk. Spiking WOS, on the other hand, signals overstock risk. The monthly demand and inventory review is when you decide what to do about both. Markdowns, promotions, early clearance — the earlier you pull those levers, the more options you have and the less margin you give up.

Step 5: Reconcile Open-to-Buy to Keep Inventory Planning on Track

Now you have what you need for a real OTB reconciliation — against actual sales, current inventory levels, updated forecasts, and confirmed commitments. This is where the demand planning process becomes genuinely useful.

Most brands at this stage have already committed to inventory with their manufacturers.

That means receipt timing becomes the primary lever. Your updated forecast combined with current WOS shows your new on hand inventory levels. As a result, you can strategically reflow inventory — avoiding excess mid-season while protecting your best sellers.

Step 6: Review Gross Margin and Net Sales to Close the Loop

Review gross margin and net sales against your plan.

This is where you assess overall business health and determine if you’re on track for the season. If markdowns run higher than planned, margin takes a hit — and you need to account for that going forward. If a category dramatically outperforms, you may have upside to capture.

Concretely, this step might mean adjusting the timing of a planned promotion because the inventory position no longer supports it. It might mean pulling a new item launch forward because you have open-to-buy and demand momentum behind it. Either way, the demand planning process isn't complete until you connect inventory performance to business performance — and update the plan to reflect both.

Why a Consistent Demand Planning Process Is Your Growth Advantage

A monthly demand and inventory review is connected steps that build on each other. When you run this demand planning process consistently, the results are concrete: you catch stockout risks before they cost you sales, you move slow movers before they eat your margin, you reflow receipts before you're over-committed, and your seasonal buys get built on current data instead of old assumptions. For product brands, inventory is the single largest expense. This process is how it stops being a liability and starts functioning as a scale and growth asset.

If you'd like support building your own process, book a call with Boon.