How do you calculate a warranty risk score for a fan?

Multiply each input by its weight and add them: field impact x 0.40 + occurrence x 0.35 + detection weakness x 0.25. With scores of 8, 4 and 3 the result is 5.35 on a 1-10 scale.

What is a good warranty risk score?

Lower is better. On the 1-10 scale, under about 3 is low risk, 3-6 is moderate (the example 5.35 sits here), and above 6-7 should trigger a design or process change before the fan ships in volume.

Why is field impact weighted highest?

At 0.40 it dominates because a fan failure in a data-center cooling or process-exhaust application can cause downtime, safety exposure and reputational damage far exceeding the part cost, so severity carries the most weight.

Warranty risk score vs traditional FMEA RPN?

Classic RPN multiplies severity x occurrence x detection (1-1000). This calculator uses a weighted sum (1-10) so the number stays interpretable and one extreme rating can't blow the total out of proportion.

How is detection weakness different from occurrence?

Occurrence is how often the failure happens; detection weakness is how likely it slips past end-of-line test and ships anyway. A vibration test that misses imbalance raises detection weakness even if occurrence is low.

Can I change the weights?

The model is fixed at 40/35/25. If your warranty cost is driven mostly by rare-but-catastrophic motor failures, treat the field-impact input as your primary lever rather than re-weighting.

Industrial Fans, Blowers & Air Movement Equipment calculator

Warranty Risk Calculator

Warranty Risk is a weighted RPN-style score that quantifies how exposed a fan or blower program is to field warranty claims before units ship. Reliability and quality engineers in air-movement OEMs use it to rank failure modes — bearing wear, motor burnout, impeller imbalance, weld cracking — so limited warranty-reduction budget goes to the worst offenders first. It matters because a single recurring failure on a high-volume centrifugal or axial fan line can erase the margin on an entire order. The score blends severity, occurrence and detectability so a high-severity-but-rare mode and a low-severity-but-frequent mode can be compared on one scale.

What this calculator does

Score warranty risk for fan and blower products from field impact, expected occurrence, and weakness of current controls.
Use it when reviewing bearing failures, vibration complaints, motor issues, coating defects, noise claims, or airflow performance risk.
It computes a single weighted warranty risk score from field impact (40%), expected occurrence (35%) and detection weakness (25%).

Formula used

Warranty risk score = field impact score × 0.40 + expected warranty occurrence score × 0.35 + warranty detection weakness score × 0.25

Inputs explained

Field impact severity if the fan fails in service:
Likelihood this warranty failure mode occurs:
Inability to detect the defect before shipment:

How to use the result

Use it during FMEA reviews, design sign-off, or supplier qualification for a fan or blower model to prioritize which warranty failure modes to mitigate first.
The weights and 1-10 inputs are subjective ratings, not measured field data — two engineers can score the same impeller defect differently, so calibrate your scoring scale before comparing across teams.

Current U.S. benchmarks

Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).

Common questions

How do you calculate a warranty risk score for a fan? Multiply each input by its weight and add them: field impact x 0.40 + occurrence x 0.35 + detection weakness x 0.25. With scores of 8, 4 and 3 the result is 5.35 on a 1-10 scale.
What is a good warranty risk score? Lower is better. On the 1-10 scale, under about 3 is low risk, 3-6 is moderate (the example 5.35 sits here), and above 6-7 should trigger a design or process change before the fan ships in volume.
Why is field impact weighted highest? At 0.40 it dominates because a fan failure in a data-center cooling or process-exhaust application can cause downtime, safety exposure and reputational damage far exceeding the part cost, so severity carries the most weight.
Warranty risk score vs traditional FMEA RPN? Classic RPN multiplies severity x occurrence x detection (1-1000). This calculator uses a weighted sum (1-10) so the number stays interpretable and one extreme rating can't blow the total out of proportion.
How is detection weakness different from occurrence? Occurrence is how often the failure happens; detection weakness is how likely it slips past end-of-line test and ships anyway. A vibration test that misses imbalance raises detection weakness even if occurrence is low.

Last reviewed 2026-05-12.