Purchase Price Variance: The Warning Sign Manufacturers Keep Missing

Most margin problems don’t show up all at once. They creep in one supplier invoice at a time, and for many manufacturers, purchase price variance is where that creep gets recorded first and noticed last.

During a recent Moore on Manufacturing episode, Mike Sibley shared valuable insights on the quiet signals manufacturers overlook while tariffs and raw material costs keep climbing. The discussion highlighted why simple metrics like PPV and product-level margins deserve more attention than they usually get.

Why Costs Are Harder to Track Right Now

Cost pressure is coming from several directions at once: tariffs, raw materials and petroleum-driven pricing. Many companies have absorbed part of those increases so far, but that won’t last forever. In Mike’s view, “we haven’t seen the full effect of price increases because of tariffs,” and more are likely in the coming months.

When costs move this often, the assumptions built into your standard costs go stale fast. Your cost assumptions “can change just like that,” and keeping up is especially hard in a high-volume operation.

What Purchase Price Variance Tells You

Purchase price variance is the gap between what you expected to pay for materials and what you actually paid. Put simply: “I thought my cost was this, but my actual cost was this, and we take that difference and we kind of blow it into the P&L.”

That’s where the trouble starts. Once the variance is buried in the P&L, it stops looking like a warning. PPV is a strong signal, but it often gets lost in the P&L or folded into material costs without anyone realizing it.

How a Small Variance Becomes a Margin Problem

The risk isn’t one big price jump. It’s a series of small ones nobody flags. Those price changes don’t get watched closely enough, and “next thing you know, your margin starts slipping a little bit.”

Why Total Margin Can Hide the Problem

Looking at margin across the whole business can give you false comfort. If some products are performing better than expected, they can cover for others losing ground to material price changes.

The fix is margin reporting by product, tracked over time and built into your monthly reporting package. That way you can see whether one product, perhaps one made with different materials, is starting to slip. Looking at the product level helps make sure “you don’t have something slipping in one area that’s being covered by another area.”

Other Indicators Worth Watching

A few related measures can give you earlier warning:

• Contribution margin, meaning your revenue minus direct costs rather than allocated overhead.
• Material costs as a percentage of revenue, tracked as a KPI.
• Price changes at the vendor level, supported by a process that lets you spot them quickly.
• Commodity markets for inputs like wood, resin, petroleum-based materials or steel. If those prices are moving, “you need to use that as an indicator for what’s to come for your business.”

Catch Cost Changes Before Months Slip By

The common thread is speed. High volume can make price changes hard to see right away, so working with your supplier base to get better visibility matters. Have a system for reviewing cost changes quickly and “don’t let months and months slip by before you’re able to react on that.”

Start with the basics. Pull PPV out of the P&L and review it each month, add margin by product to your reporting package and watch the commodity prices that drive your inputs.

If your total margin looked fine last month, do you know whether every product line actually held?

Watch the full episode of Moore on Manufacturing to hear Mike’s complete conversation on tariffs, supplier strategy and building resilience over the next 12 months.

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