Measurement, Test & Control Equipment worked example

Component Tolerance Stack Risk with severity score of 3.5 1-10: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop severity score to 3.5 1-10, then walk the calculation through step by step. Score the risk of tolerance stack-up failures in assemblies that affect measurement accuracy or test equipment performance. Uses severity, occurrence, and detection scoring similar to FMEA methodology.

The inputs for this scenario

  • Severity score: 3.5 1-10 (the input this scenario stresses; the baseline uses 7)
  • Occurrence score: 4 1-10 (held at the documented default)
  • Detection score: 5 1-10 (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Risk priority number (RPN) = severity score x occurrence score x detection score.
  • Risk priority number (RPN) works out to 4.05 score at these inputs, and this is the headline figure for the scenario.
  • Severity score works out to 3.5 score at these inputs.
  • Occurrence score works out to 4 score at these inputs.
  • Detection score works out to 5 score at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where severity score sits at 7 1-10 and the headline result is 5.45 score, this scenario comes in 25.69% below the baseline at 4.05 score.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to severity score, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. RPN is ordinal, not a probability, and equal RPNs can hide very different risk profiles, so always review the underlying severity score independently.

Results at a glance

  • Risk priority number (RPN): 4.05 score (headline result)
  • Severity score: 3.5 score
  • Occurrence score: 4 score
  • Detection score: 5 score

Run it with your numbers

  • To rerun this with your own numbers, open the live Component Tolerance Stack Risk calculator, set severity score to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.