Transformers, Coils & Magnetics Manufacturing worked example

Core Loss Estimate with severity of core-loss failure of 3 score: a worked example

This worked example runs the core loss estimate numbers for a tougher week than the baseline: severity of core-loss failure of 3 score instead of the typical 6 score. Core Loss Estimate turns three FMEA-style ratings — severity, occurrence and detection — into a single weighted risk score for excess core loss in a transformer or inductor.

The inputs for this scenario

  • Severity of core-loss failure: 3 score (the input this scenario stresses; the baseline uses 6)
  • Occurrence likelihood of excess core loss: 4 score (held at the documented default)
  • Detection difficulty before shipment: 3 score (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Core Loss Estimate risk score = severity × 0.40 + occurrence × 0.35 + detection × 0.25.
  • Risk score works out to 3.35 score at these inputs, and this is the headline figure for the scenario.
  • Severity works out to 3 score at these inputs.
  • Occurrence works out to 4 score at these inputs.
  • Detection works out to 3 score at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where severity of core-loss failure sits at 6 score and the headline result is 4.55 score, this scenario comes in 26.37% below the baseline at 3.35 score.
  • Use it during a magnetics FMEA or design review to prioritize core-loss failure modes and QA effort. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Risk score: 3.35 score (headline result)
  • Severity: 3 score
  • Occurrence: 4 score
  • Detection: 3 score

Run it with your numbers

  • To rerun this with your own numbers, open the live Core Loss Estimate calculator, set severity of core-loss failure to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.