Quiet failures: the risks your DFMEA found but your customers paid for.
If poor product quality is slowly eroding your customer base, look for quiet failures.
You'll find them in your DFMEA. They just scored below your action threshold.
Loud failures and quiet ones
In consumer products, you hear about the loud failures: catastrophic breaks, safety issues, one-star reviews with a photo. Those are the ones that escalate to the big bosses, and the ones the whole system is built to catch.
The quiet ones are more common. A gasket eventually lets a drip or two through. A hinge starts to squeak. Gears get sloppy. A finish dulls. None of it drives a formal complaint. But the customer notices, and says to themself, "Why do I pay extra for this brand when it doesn't last any longer?"
Why the DFMEA lets them through
Those failures were predictable, and most of them made it into the DFMEA. Then the scoring did exactly what it was designed to do:
- Nobody gets hurt, so severity is low.
- The product still works, for the most part, so nothing feels urgent.
- The risk lands under the action line, and the row sits there for the life of the product.
Severity scales are built to rank harm and loss of function, and they do that well. They're not built to rank the slow erosion of a customer's opinion. A squeak at year two scores like an annoyance, because to any one customer it is one.
Why the field agrees with the DFMEA
Quiet failures don't show up in returns, complaints or warranty claims. Nobody ships a squeaky hinge back. They live with it, and they remember it.
So the low score and the silent field agree with each other. The team reads that agreement as success and moves on.
That's the trap. Warranty data measures what customers complain about, not what they notice. A silent field isn't a satisfied one; it can be a field full of customers who've quietly decided not to buy from you again.
What to do about it
- Review the rows below the line as a group. Pull every row under your action threshold and sort by effect. The drips, squeaks, rattles, play and fading that show up again and again are your quiet failures. Individually they're minor. Together they're a brand problem.
- Ask what the customer notices at year two, not day one. Most quiet failures are wear and drift. If your product is sold on lasting longer, a failure mode that makes it feel worn early cuts against the reason people paid for it.
- Look past warranty. Read the three-star reviews, not just the one-star ones. "Works fine, feels cheap" is a quiet failure reporting in.
- Test for degradation, not just function. A life test that only checks whether the product still works will pass a product that drips, squeaks and wobbles. Look for the change, not just the failure.
Where RiskForge fits
RiskForge writes the quiet failure modes alongside the loud ones (wear, drift, loosening, appearance) and ties each one to a test in the DVP&R, so a row that sits below the line still has a test that would show it happening. Whether to act on it stays your team's call. The difference is that the decision gets made with the risk in view, not by default.
How many un-actioned quiet failures are costing you customers?