Data Insights — Business & Supply Chain

Inventory Control

Fewer stockouts, less dead capital — without a lengthy IT project

Rob den Otter April 2026 3 minute read Business & Supply Chain

What you'll take from this

Your warehouse looks like an asset on the balance sheet. Stock that doesn't move costs you 18–25% of its value per year — in space, write-offs, and tied-up cash.

The two KPIs that actually matter are inventory turnover rate and GMROI — not just how much you have in stock.

Power BI connects directly to your ERP or WMS and flags exceptions automatically: what's running low, what hasn't moved in six months, what's consuming storage without generating revenue.

One wholesaler freed up €150,000 in working capital by cutting C-items that occupied 30% of warehouse space while generating just 3% of profit. The data made the decision obvious.

“Do you still have this in stock?” It’s the question every entrepreneur dreads when the answer is “no.” A rejected order feels like failure — you lose the sale and possibly the customer. The natural reaction is to buy more, broaden the range, order an extra pallet “just in case.” But in 2026, that strategy is a silent profit killer.

Inventory Turnover Rate

How many times do I sell my average inventory per year?

A low turnover rate means tied-up money generating nothing. An extremely high turnover rate means you're regularly turning down orders. You're looking for the sweet spot per product group — and it's different for every category.

GMROI

For every euro I invest in inventory, how much profit do I get back?

GMROI combines margin with velocity — the purchasing manager's holy grail. A low-margin product that sells quickly (copy paper) can be more profitable than a high-margin product sitting idle for a year. Without this combination, you're managing blind.

Practical case

A wholesaler believed they had to "have everything in stock." Data analysis revealed that 40% of their inventory (C-items) generated just 3% of their profit while consuming 30% of warehouse space. Cutting those items freed up €150,000 in working capital immediately — without making a single additional euro in revenue.

Clean up your product file

Duplicate items, incorrect lead times, missing product groups — fix these first. Dirty data leads to wrong purchasing decisions, regardless of how good your dashboard is.

Run a dormant stock check

Create a list of everything that hasn't sold in the past 12 months. Plan an action: clearance sale, return to supplier, or write-off. This releases working capital immediately.

Start measuring

Stop relying on gut feel ("I think this will sell") and start managing on trends. Even a basic ERP report is a better foundation than experience alone.

The conclusion: you can't manage what you can't see

Inventory management is not a warehouse problem — it's an information problem. As long as you buy on intuition and control with Excel, you're paying invisible costs that come directly out of your margin: storage space for items nobody orders, missed revenue on items that run out too early, and working capital tied up in boxes that haven't moved in months.

Den Otter Solutions helps Dutch SMEs make these costs visible and manageable through Power BI dashboards

Frequently asked questions

Does Power BI work if our inventory data is in Excel or Google Sheets?

Yes. Excel and Google Sheets are some of the most common starting points and works well as a Power BI data source. A daily scheduled export from your ERP or WMS delivers 90% of the value — without complex live connections. Most clients start this way and only move to a direct connection later if the added value justifies it.

How do we know which products are truly slow-moving versus just seasonal?

This is exactly where an ABC/XYZ analysis adds value. ABC categorises by revenue contribution; XYZ by demand predictability. A product that sells only in winter is not slow — it's seasonal (Z-class). A product with no movement in 12 months and no seasonal pattern is a genuine dead stock candidate. Power BI calculates both dimensions automatically once your data is connected.

How quickly do we see results after implementing an inventory dashboard?

Most businesses see actionable insights within the first week — specifically which items need attention first. The real results (lower inventory costs, fewer stockouts, more liquidity) develop over the following months as purchasing decisions consistently move from gut feel to data.

Do we need an in-house data analyst to maintain this?

No. Den Otter Solutions' Analytics as a Service fills exactly this role — as a flexible external data partner for SMEs without an internal data team. You get the expertise of a supply chain specialist and Power BI consultant, without the fixed staffing costs.