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Industry context: FMEA is used across aerospace (ARP 4761), automotive (AIAG-VDA), and medical device (ISO 14971) industries. The DFMEA variant uses RPN (Risk Priority Number = Severity x Occurrence x Detection) for risk prioritization. The newer AIAG-VDA methodology replaces numeric RPN with logic-based Action Priority (H/M/L) for more meaningful risk ranking. diagram

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Levels Configuration

Three levels define the FMEA hierarchy. The system element (or characteristic) is the top-level grouping item, failure modes are analyzed per element, and causes are identified per failure mode. 
"levels": [
    { "name": "System Element", "controlColumn": "title", "zoomColumn": "title" },
    { "name": "Failure Mode", "controlColumn": "failureMode", "zoomColumn": "failureMode" },
    { "name": "Cause", "zoomColumn": "cause", "controlColumn": "cause" }
]

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Column Definitions

Key columns with data type bindings. Severity, occurrence, and detection are enum fields scored 1-10. RPN columns use formulas for computed values. 
"columns": [
    { "id": "title", "binding": "title", "title": "System Element",
      "width": 200, "headerClass": "headElement" },
    { "id": "failureMode", "binding": "failureMode", "title": "Failure Mode",
      "width": 200, "headerClass": "headFailure" },
    { "id": "cause", "binding": "cause", "title": "Cause",
      "width": 200, "headerClass": "headFailure" },
    { "id": "effect", "binding": "effect", "title": "Effect",
      "width": 200, "headerClass": "headFailure" },
    { "id": "sev", "binding": "sev", "title": "Sev", "dataType": "enum",
      "width": 60, "headerClass": "headRisk" },
    { "id": "occ", "binding": "occ", "title": "Occ", "dataType": "enum",
      "width": 60, "headerClass": "headRisk" },
    { "id": "det", "binding": "det", "title": "Det", "dataType": "enum",
      "width": 60, "headerClass": "headRisk" },
    { "id": "rpn", "binding": "rpn", "title": "RPN",
      "formula": "commonRpn", "width": 70, "headerClass": "headRisk" },
    { "id": "mitigation", "binding": "mitigation", "title": "Mitigation",
      "type": "taskLink", "width": 200, "headerClass": "headMitigation" },
    { "id": "occNew", "binding": "occNew", "title": "Occ'", "dataType": "enum",
      "width": 60, "headerClass": "headRevised" },
    { "id": "detNew", "binding": "detNew", "title": "Det'", "dataType": "enum",
      "width": 60, "headerClass": "headRevised" },
    { "id": "rpnNew", "binding": "rpnNew", "title": "RPN'",
      "formula": "commonRpnNew", "width": 70, "headerClass": "headRevised" }
]

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Formulas

Multiplies severity, occurrence, and detection to produce the initial Risk Priority Number (1-1000 scale).
"commonRpn": "function(info) {
  var s = info.item['sev'];
  var o = info.item['occ'];
  var d = info.item['det'];
  if (!s || !o || !d) return null;
  return parseInt(s) * parseInt(o) * parseInt(d);
}"
Recalculates RPN after mitigation actions using the updated occurrence and detection values. Severity does not change after mitigation.
"commonRpnNew": "function(info) {
  var s = info.item['sev'];
  var o = info.item['occNew'];
  var d = info.item['detNew'];
  if (!s || !o || !d) return null;
  return parseInt(s) * parseInt(o) * parseInt(d);
}"
Logic-based risk prioritization replacing numeric RPN multiplication. Returns H (High), M (Medium), or L (Low) based on severity, occurrence, and detection thresholds. Used in Process FMEA configurations.
"commonAP": "function(info) {
  var s = info.item['sev'];
  var o = info.item['occ'];
  var d = info.item['det'];
  if (!s || !o || !d) return null;
  s = parseInt(s); o = parseInt(o); d = parseInt(d);
  if (s >= 9) return 'H';
  if (s >= 5 && o >= 4) return 'H';
  if (s >= 5 || o >= 4 || d >= 6) return 'M';
  return 'L';
}"
PriorityMeaningCriteria
H (High)Immediate action requiredSeverity >= 9, or Severity >= 5 AND Occurrence >= 4
M (Medium)Action recommendedSeverity >= 5, or Occurrence >= 4, or Detection >= 6
L (Low)Action optionalAll other combinations

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Formatters

Color-codes severity values from critical (red) through negligible (green). Applied to the severity column.
"severityFormatter": [
  { "expression": "context.value >= 4", "style": "sevCritical" },
  { "expression": "context.value == 3", "style": "sevMajor" },
  { "expression": "context.value == 2", "style": "sevMinor" },
  { "expression": "context.value <= 1 && context.value > 0", "style": "sevNegligible" }
]
SeverityColorStyle
Critical (>= 4)RedbackgroundColor: red100, color: red700
Major (3)OrangebackgroundColor: orange100, color: orange800
Minor (2)YellowbackgroundColor: yellow100, color: yellow900
Negligible (<= 1)GreenbackgroundColor: green100, color: green800
Colors RPN cells based on risk thresholds. Includes inline labels (Low/Medium/High) below the numeric value.
"rpn": "function(info) {
  var val = info.value;
  $(info.cell).toggleClass('rpn1', val > 0 && val <= 10);
  $(info.cell).toggleClass('rpn2', val > 0 && val > 10 && val <= 30);
  $(info.cell).toggleClass('rpn3', val > 0 && val > 30);
  if (val > 0) {
    var label = val <= 10 ? 'Low' : (val <= 30 ? 'Medium' : 'High');
    var color = val <= 10 ? '#4caf50' : (val <= 30 ? '#ff9800' : '#f44336');
    info.cell.innerHTML = val + '<br><span style=\"font-size:12px;color:'
                        + color + '\">' + label + '</span>';
  }
}"
RPN RangeLabelColor
1 — 10LowGreen (#4caf50)
11 — 30MediumOrange (#ff9800)
> 30HighRed (#f44336)

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Workflow Views

Ten views guide analysts through the complete FMEA process from identification through verification. 
"views": [
    { "name": "Default", "defaultView": true },
    { "name": "No Up/Down Risks",
      "columnIds": ["title", "failureMode", "cause", "effect",
                    "sev", "occ", "det", "rpn",
                    "mitigation", "occNew", "detNew", "rpnNew"] },
    { "name": "1. Identify Failure Modes",
      "columnIds": ["title", "failureMode", "cause", "effect"] },
    { "name": "2. Initial Risk Ranking",
      "columnIds": ["title", "failureMode", "sev", "occ", "det", "rpn"] },
    { "name": "3. Link Downstream DFMEA",
      "columnIds": ["title", "failureMode", "rpn", "downstreamRisk"] },
    { "name": "4. Define Mitigations",
      "columnIds": ["title", "failureMode", "rpn", "mitigation"] },
    { "name": "5. Verify Controls",
      "columnIds": ["title", "failureMode", "mitigation", "occNew", "detNew"] },
    { "name": "6. Final Risk Evaluation",
      "columnIds": ["title", "failureMode", "rpn", "rpnNew", "mitigation"] },
    { "name": "7. Risk Summary",
      "columnIds": ["title", "failureMode", "sev", "rpn", "rpnNew"] },
    { "name": "Full View", "columnIds": ["@all"] }
]
The FMEA cascade uses multiItemLink columns to connect failure modes across System, Subsystem, and Component FMEA documents. This creates traceable risk chains from top-level system failures down to individual component failure modes. 
"upstreamRisk": {
    "id": "upstreamRisk",
    "title": "Upstream Risk",
    "type": "multiItemLink",
    "linkRole": "causes",
    "backLink": true,
    "width": 200
},
"downstreamRisk": {
    "id": "downstreamRisk",
    "title": "Downstream Risk",
    "type": "multiItemLink",
    "linkRole": "causes",
    "backLink": false,
    "width": 200
}
The cascade hierarchy links three FMEA levels: 
System FMEA (customer requirements level)
  └── Subsystem FMEA (function level)  ← bidirectional upstream/downstream
        └── Component DFMEA (characteristic level)

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Key Patterns

  • Dual RPN assessment — pre-mitigation RPN (S x O x D) and post-mitigation RPN (S x O' x D') on the same row, showing risk reduction at a glance. Severity stays constant because mitigation doesn’t change failure impact.
  • Action Priority as RPN alternative — the AIAG-VDA logic-based AP formula provides more meaningful risk ranking than numeric multiplication. High severity always requires action regardless of occurrence/detection.
  • 3-tier RPN color coding — inline labels (Low/Medium/High) appear below the numeric RPN value with color-matched text, making risk levels scannable without memorizing threshold values.
  • FMEA cascade via multiItemLink — upstream and downstream columns connect System, Subsystem, and Component FMEAs with backLink: true/false, enabling full failure chain traceability across documents.
  • 10-step guided workflow — views walk analysts from identification through verification in a prescribed sequence, reducing errors by showing only relevant columns at each step.
  • SC/CC classification badges — inline-styled pill rendering (orange for Safety-Critical, red for Certification-Critical) provides instant classification visibility.

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See Also