Incident Cause Finder Calculator

Values are illustrative. Your scores should follow your internal scoring guide.

• RPN = Severity × Occurrence × Detection.
• Total Impact Cost = (Downtime Hours × Cost per Hour) + (Scrap Units × Scrap Cost) + (Rework Hours × Rework Cost) + Customer Cost.
• Cause Likelihood Index for each 6M category = Evidence Score × Category Weight.
• Top Cause = category with the highest weighted index.
• Cause Confidence = Top Index ÷ Sum of All Indices × 100.
• APS = RPN × (1 + Recurrence/10) + (Total Cost/100) + (100 − Containment %)/2.

APS is a practical prioritization score that blends risk, repeat frequency, impact, and containment strength.

1. Enter incident details, then score Severity, Occurrence, and Detection.
2. Add recurrence count and your current containment effectiveness estimate.
3. Fill impact inputs using your standard hourly and unit cost rates.
4. Rate evidence (0–5) for each 6M cause family.
5. Press Submit & Analyze to view results above the form.
6. Use the CSV/PDF buttons to export and share your report.

For best results, align scoring scales to your internal FMEA or CAPA procedures.

Incident Data Quality Baseline

Use consistent incident IDs, dates, and process-step naming to avoid duplicate records. Track defect type, detection method, lot, shift, and tool or fixture identifiers. In many factories, 15–25% of incident logs miss at least one traceability field, which weakens trend analysis and delays containment. A minimum dataset enables faster escalation, clearer comparisons, and stronger evidence scoring across teams.

Scoring Discipline for S, O, D

Severity, Occurrence, and Detection scores should follow one internal scale. Calibrate scorers quarterly with examples so a “7” means the same across lines. When Detection improves through better tests, the RPN will drop even if the defect still occurs. Set Detection based on control strength and escape likelihood, not inspection effort alone. Treat the scores as signals, not blame, and document the rationale for each rating in the notes field.

Evidence-to-Cause Mapping with 6M

The calculator uses 6M categories to structure hypotheses: Man, Machine, Method, Material, Measurement, and Environment. Evidence scores (0–5) represent how direct the proof is, such as gage data or alarms. Weights adjust realism by incident type, so a breakdown elevates Machine evidence, while supplier issues elevate Material evidence. The top category confidence rises when one index dominates the total; use low confidence as a cue to collect more measurements.

Cost Impact Modeling for Decisions

A quality response is stronger when risk and money align. Total Impact Cost combines downtime, scrap, rework, and customer costs using your rates and currency. Include hidden costs such as expedited freight, extra inspections, sorting labor, and warranty handling. Even small RPN incidents can justify action if cost per hour or customer exposure is high. Scenario runs help: adjust downtime or scrap to see how priorities shift before committing resources.

Prioritization and Verification Loop

Action Priority Score blends RPN, recurrence, containment strength, and cost into one queue. Use the action level to set owners and deadlines, then verify effectiveness with a before/after metric: defect rate, alarm frequency, first-pass yield, or audit results. Track verification within 30 days for high priorities and document residual risk. Close the loop by updating SOPs, training, and control plans, and keep monitoring recurrence to prevent silent drift.

1) What does RPN represent in this calculator?

RPN multiplies Severity, Occurrence, and Detection to express relative risk. Use it to compare incidents using the same scoring guide. Higher values demand faster action, especially when the issue can escape to customers or regulators.

2) How should I choose the 0–5 evidence scores?

Score 0 when there is no supporting evidence and 5 when evidence is direct and repeatable, like measured data, alarms, or verified observations. Keep scores consistent across teams and summarize proof in the notes field.

3) Why do cause weights change with incident type?

Weights reflect typical failure patterns. For example, breakdowns usually point to Machine or Method, while supplier issues often point to Material. Weighting helps the cause ranking match reality without forcing you to change evidence scores.

4) What is APS, and how should I use it?

APS blends RPN with recurrence, containment effectiveness, and cost impact. Use it to create an action queue: stop-and-contain items first, then rapid corrective, then planned improvements. Recalculate after controls change to confirm priority drops.

5) Can I use this for near-miss events?

Yes. Treat near-miss events as learning opportunities. Assign Severity based on potential impact, not the actual outcome, and capture recurrence and evidence. This keeps preventive actions visible before a true escape occurs.

6) How do I validate the top cause category?

Validate by checking the strongest evidence first, then running targeted tests or audits. If confidence is low, gather more measurements and re-score. Confirm effectiveness with a before/after metric such as defect rate or first-pass yield.