When to Activate This Skill
- "Create a PFMEA for [process]"
- "What are the failure modes for [operation]?"
- "Calculate RPN for [risk scenario]"
- "Rate severity/occurrence/detection for [failure]"
- "Identify process risks"
- "FMEA analysis for [part/process]"
CRITICAL: Always Generate Content Directly
Every response to a PFMEA request MUST contain the actual PFMEA analysis inline — failure modes, S/O/D ratings, RPN/AP, controls, and actions written out in full. Never respond with only a plan, a reference to loading files, or an empty/deferred answer. Supplementary file reads (CLAUDE.md, templates, reference docs) are OPTIONAL background lookups — they must never replace or delay producing the actual PFMEA content in this response.
AIAG-VDA 7-Step Methodology
Step 1: Planning and Preparation
- Define scope and boundaries
- Identify team members (cross-functional)
- Gather documentation (process flow, control plan, drawings)
- Review lessons learned from similar processes
Step 2: Structure Analysis
- Define process steps from process flow diagram
- Create process tree (System > Sub-system > Process Element)
- Identify interfaces between steps
- Link to product characteristics
Step 3: Function Analysis
- Define function of each process step
- Identify product/process requirements
- Link to customer/engineering specifications
- Document special characteristics (CC/SC)
Step 4: Failure Analysis
- Identify failure modes (how can step fail to perform function?)
- Determine failure effects (consequences to customer/next operation)
- Identify failure causes (why would failure mode occur?)
- Chain: Cause → Failure Mode → Effect
Step 5: Risk Analysis
- Rate Severity (S) of effects: 1-10
- Rate Occurrence (O) of causes: 1-10
- Rate Detection (D) of controls: 1-10
- Calculate Action Priority (AP) or RPN
Step 6: Optimization
- Prioritize high-risk items
- Develop countermeasures (hierarchy: Eliminate > Substitute > Engineer > Admin > Detect)
- Assign responsibility and target dates
- Re-rate after countermeasures
Step 7: Results Documentation
- Document all analysis
- Track countermeasure completion
- Update Control Plan linkage
- Archive for lessons learned
Rating Scales (MNMUK Standard)
Severity (S) - Effect on Customer/Process
| Rating | Criteria | MNMUK Examples |
|---|---|---|
| 10 | Affects safety without warning | Brake component failure, no containment possible |
| 9 | Affects safety with warning | Safety critical dimension OOS, detectable at assembly |
| 8 | Product inoperable, 100% scrap | Part cannot be reworked, total loss |
| 7 | Product operable but degraded, customer dissatisfied | Performance below spec, customer complaint |
| 6 | Product operable, comfort/convenience affected | Cosmetic defect, minor fit issue |
| 5 | 50% of product may need rework | Significant rework required |
| 4 | Product requires sorting/rework | Sorting operation needed |
| 3 | Minor rework at station | In-station repair possible |
| 2 | Slight inconvenience | Minor adjustment |
| 1 | No effect | No discernible impact |
Occurrence (O) - Likelihood of Cause
| Rating | Failure Rate | Cpk Equivalent | MNMUK Examples |
|---|---|---|---|
| 10 | Very high: ≥100/1000 | <0.33 | New process, no controls |
| 9 | High: 50/1000 | ≥0.33 | Known problem process |
| 8 | High: 20/1000 | ≥0.51 | Similar process had failures |
| 7 | Moderately high: 10/1000 | ≥0.67 | Occasional failures observed |
| 6 | Moderate: 2/1000 | ≥0.83 | Infrequent failures |
| 5 | Moderately low: 0.5/1000 | ≥1.00 | Controlled process, some failures |
| 4 | Low: 0.1/1000 | ≥1.17 | Well-controlled process |
| 3 | Very low: 0.01/1000 | ≥1.33 | Capable and controlled |
| 2 | Remote: 0.001/1000 | ≥1.50 | Proven design and controls |
| 1 | Nearly impossible: ≤0.001/1000 | ≥1.67 | Failure eliminated by design |
Detection (D) - Ability to Detect Before Customer
| Rating | Detection Capability | MNMUK Examples |
|---|---|---|
| 10 | No detection possible | No inspection, no opportunity to detect |
| 9 | Unlikely to detect | Random sampling only, infrequent |
| 8 | Low: Visual inspection by operator | 100% visual check, variable attention |
| 7 | Very low: Double visual inspection | Two operators check |
| 6 | Low: Charting/SPC | Control charts, trend monitoring |
| 5 | Moderate: Attribute gaging | Go/No-go gaging |
| 4 | Moderately high: Variable gaging | Measurement with limit checking |
| 3 | High: Automated in-process test | Automatic measurement, alarm |
| 2 | Very high: Error-proofing | Poka-yoke prevents defect production |
| 1 | Almost certain: Error-proofing prevents cause | Design makes failure impossible |
Action Priority (AIAG-VDA Approach)
Instead of or in addition to RPN, use Action Priority:
| Priority | Criteria | Action Required |
|---|---|---|
| HIGH | S=9-10 (any O, D) OR S=7-8 with O≥4 AND D≥4 | Immediate action required |
| MEDIUM | S=5-8 with O≥4 OR D≥4 | Action recommended |
| LOW | All others | Monitor and document |
RPN Thresholds (MNMUK Standard)
| RPN Range | Priority | Required Action |
|---|---|---|
| ≥120 | Critical | Immediate countermeasure, cannot ship without action |
| 80-119 | High | Countermeasure required before PPAP |
| 40-79 | Medium | Countermeasure recommended |
| <40 | Low | Monitor, no immediate action |
Note: Any Severity ≥8 requires action regardless of RPN.
Countermeasure Hierarchy
When addressing failure modes, apply controls in this priority order:
- Eliminate - Design out the failure mode entirely
- Substitute - Replace with less hazardous process/material
- Engineer - Install physical safeguards, poka-yoke
- Admin - Procedures, training, work instructions
- Detect - Inspection, testing, monitoring
Special Characteristics
Critical Characteristics (CC)
- Safety or regulatory impact
- Marked with shield symbol or (CC)
- Requires enhanced controls
- Mandatory documentation
Significant Characteristics (SC)
- Fit, function, or durability impact
- Marked with diamond or (SC)
- Requires appropriate controls
- SPC typically required
Output Format Requirements
CRITICAL: Every PFMEA response MUST be complete. Never truncate or cut off mid-entry. Every failure mode listed MUST have:
- All causes fully documented
- S/O/D ratings for EVERY cause row
- RPN calculated for EVERY row
- Current controls listed
- Recommended actions specified
- After-action ratings included
If the full PFMEA would be very long, reduce the NUMBER of failure modes covered, but each one included MUST be 100% complete. Do not start a failure mode entry you cannot finish.
Output Format
When generating PFMEA content:
# PFMEA: [Part/Process Name]
**Part Number**: [P/N]
**Process**: [Description]
**FMEA Number**: PFMEA-[DEPT]-[SEQ]
**Revision**: [Rev] | **Date**: [YYYY-MM-DD]
**Team**: [Names/Roles]
## Process Step: [Step Name]
### Failure Mode 1: [Description]
**Function**: [What the step should do]
**Effect**: [What happens if it fails]
**Cause**: [Why it would fail]
| S | O | D | RPN | AP |
|---|---|---|-----|-----|
| X | X | X | XXX | H/M/L |
**Current Controls**:
- Prevention: [Current prevention measures]
- Detection: [Current detection measures]
**Recommended Actions**:
- [ ] [Action description] - Owner: [Name] - Due: [Date]
**After Action**:
| S | O | D | RPN | AP |
|---|---|---|-----|-----|
| X | X | X | XXX | H/M/L |
Department-Specific Guidance
Machine Shop
- Common failure modes: Dimensional OOS, surface finish, tool wear
- Focus on: Fixturing, program parameters, tool life management
- Key controls: First piece inspection, SPC, gage R&R
Damper Assembly
- Common failure modes: Leak, incorrect torque, missing component
- Focus on: Seal integrity, fastener torque, component presence
- Key controls: Leak test, torque verification, poka-yoke
LVA (Low Volume Assembly)
- Common failure modes: Wrong component, incorrect orientation, damage
- Focus on: Part identification, assembly sequence, handling
- Key controls: Visual verification, traveler documentation
FML (Final Manufacturing Line)
- Common failure modes: Test failure, labeling error, packaging damage
- Focus on: Final test parameters, traceability, packaging
- Key controls: Automated test, barcode verification, packaging audit
Integration with Related Skills
ControlPlan
PFMEA feeds directly into Control Plan:
- High S/O items require enhanced inspection
- Detection controls become Control Plan methods
- Special characteristics flow to Control Plan
Load: read ~/.claude/skills/Controlplan/SKILL.md
AutomotiveManufacturing
Work instructions should reflect PFMEA findings:
- High-risk steps highlighted
- Operator controls documented
- Quality checkpoints specified
Load: read ~/.claude/skills/Automotivemanufacturing/SKILL.md
A3criticalthinking
When PFMEA reveals issues:
- Use 5 Whys for root cause analysis
- Fishbone diagram for cause identification
- A3 format for countermeasure planning
Load: read ~/.claude/skills/A3criticalthinking/SKILL.md
Workflow Routing
| Trigger | What to do |
|---|---|
| "create a PFMEA for [process]" / "FMEA analysis for [part/process]" | Run the full AIAG-VDA 7-Step Methodology; emit the Output Format markdown with one Failure Mode block per row, S/O/D + RPN + AP for every cause, current controls, recommended actions, and after-action re-rating |
| "what are the failure modes for [operation]?" | Use Failure Analysis (Step 4) plus reference/common-failure-modes.md for the relevant department; chain Cause → Failure Mode → Effect for each candidate |
| "rate severity/occurrence/detection for [failure]" / "calculate RPN for [scenario]" | Apply the Rating Scales tables (S/O/D) and compute RPN + Action Priority per the Action Priority and RPN Thresholds tables; flag S≥8 as requiring action regardless of RPN |
| "identify process risks" / dept-specific PFMEA (Machine Shop, Damper, LVA, FML) | Apply the matching Department-Specific Guidance block for common failure modes, focus areas, and key controls before running Steps 1-7 |
| "what countermeasure / how do we fix this failure mode?" | Apply the Countermeasure Hierarchy (Eliminate > Substitute > Engineer > Admin > Detect) — never default to an added inspection when a higher-tier fix is feasible |
| "link PFMEA to control plan" / "special characteristics" | Use Special Characteristics (CC/SC) rules, then hand off to the ControlPlan skill per Integration with Related Skills |
| "PFMEA calibration session" / "team composition" / "review triggers" / advanced/edge-case PFMEA questions | read ~/.claude/skills/Pfmea/CLAUDE.md for team composition, rating calibration, control effectiveness matrix, and update triggers |
Examples
Example 1 — Full PFMEA for a machining operation
User: "Create a PFMEA for the damper rod OD turning operation on the CITIZEN Swiss lathe."
Output: AIAG-VDA 7-step PFMEA in the skill's Output Format — process step "Turn Rod OD to spec" with failure modes (oversize/undersize OD, poor surface finish, chatter marks), each with Function/Effect/Cause, S/O/D ratings, RPN, Action Priority, current prevention/detection controls, recommended actions with owner/due date, and after-action re-rating. Machine Shop department guidance applied (fixturing, tool wear, first-piece inspection per Department-Specific Guidance).
Example 2 — Rating a single failure mode
User: "Rate severity, occurrence, and detection for a missed damper gas charge — dampers ship without gas."
Output: S=8 (product inoperable) or S=9 if the application is safety-critical, per the Severity table. O rated against current process controls (e.g., O=6 for a manual charge station with no verification). D rated against current detection (e.g., D=7 if only an end-of-line function test is relied on). RPN calculated, Action Priority flagged HIGH (S≥8), and the Countermeasure Hierarchy applied to recommend an Engineer-tier fix (weight-check or pressure sensor poka-yoke) over adding another visual inspection.
Example 3 — Escalating a PFMEA finding into Control Plan and 8D
User: "Our LVA PFMEA shows wrong-component assembly at RPN 144. What next?"
Output: Flags RPN ≥120 as Critical per RPN Thresholds — immediate countermeasure required, cannot ship without action. Recommends an Eliminate/Engineer-tier fix (kitting with poka-yoke tray, component-presence sensor) over an Admin-tier fix (visual check procedure). Links the finding to the ControlPlan skill to convert the new detection control into a Control Plan line, and to A3criticalthinking for 5-Whys root cause analysis if the wrong-component issue has already occurred in production.
Supplementary Resources
For detailed guidance:
read ~/.claude/skills/Pfmea/CLAUDE.md
For templates:
ls ~/.claude/skills/Pfmea/templates/
For rating scales:
read ~/.claude/skills/Pfmea/reference/rating-scales.md
For common failure modes:
read ~/.claude/skills/Pfmea/reference/common-failure-modes.md