The failure mode detection enumeration defines a six-level scale (0-5) rating how likely a failure mode is to be detected before it reaches the end user or patient.
In this solution, higher detection values mean the failure IS MORE likely to be detected. This may differ from the traditional AIAG FMEA convention where 1 = almost certain detection and 10 = virtually undetectable. Ensure your team understands the scale direction when performing assessments.
Because higher detection values mean better detection capability, the RPN behavior differs from traditional FMEA conventions:
Detection Rating
Detection Capability
Effect on RPN
1 (Never)
Almost no detection
Increases RPN (bad)
5 (Always)
Near-certain detection
Increases RPN (counterintuitive)
In this solution’s scale, D=5 (Always detected) produces a higher RPN than D=1 (Never detected) for the same S and O values. This is the inverse of the traditional AIAG convention. When comparing RPN thresholds with industry standards or external auditors, account for this scale direction.Example: S=4, O=3, D=5 yields RPN=60, while S=4, O=3, D=1 yields RPN=12. The more detectable failure has the higher RPN, which may require adjusted RPN threshold definitions.
The detection and occurrence enumerations share identical labels and probability ranges but carry different meanings:
Property
Occurrence
Detection
Measures
How often the failure occurs
How likely the failure is detected
Rating 1
Never occurs (<5%)
Never detected (<5%)
Rating 5
Always occurs (>95%)
Always detected (>95%)
Visual indicators
Shared labels, no unique icons
No icons or colors defined
Unlike severity (which has color-coded RPN icons) and occurrence (which has labels), the detection enumeration has no icons or colors configured. Detection cells in risksheet display plain text values only.
RPN = Severity (S) x Occurrence (O) x Detection (D)Pre-mitigation: S x premitigationFMOccurrence x premitigationDetection = premitigationRPNPost-mitigation: S x postmitigationFMOccurrence x postmitigationDetection = postmitigationRPN
Detection improvements are a common risk mitigation strategy when the root cause cannot be eliminated:
