🧭 Why Step 7 matters #
This step turns months of analysis and optimization into clear, auditable evidence. It proves risks are controlled, actions are closed, and the production system will keep them controlled.
Deliverables at a glance
- PFMEA Summary Table (status, risks, actions, sign-offs)
- Residual Risk Register (with acceptance)
- Final Process Control Plan (linked to PFMEA rows)
- Traceability & Evidence Map (MES/SPC/MSA/PM logs)
- Lessons Learned & change-control references
- PPAP / Audit Pack ready for submission or review
1) PFMEA Summary Table (one-page view) #
Snapshot the line’s risk posture and closure status. Paste this as the first tab or a cover sheet.
| Field | Content (EWP example) |
|---|---|
| Process / Line | EWP Final Assembly & EoL (Line-EWP-01) |
| PFMEA Rev / Date | Rev 1.4 / 06-Sep-2025 |
| Scope | OP01–OP14 incl. in-line & EoL tests; rework/quarantine flow |
| Special Characteristics | 🔺 Flow ≥ 35 L/min @ 20 kPa; 🔧 Leak ≤ 0.5 ml/min @ 1.5 bar; 🎯 Torque 4.0 ± 0.3 N·m; 🎯 Press-fit depth 12.00 ± 0.05 mm; 🎯 ESD < 100 V |
| AP-High (Open / Total) | 0 / 7 (all mitigated or accepted) |
| AP-Medium (Open / Total) | 2 / 10 (closure targeted by 30-Sep-2025) |
| Key Improvements | Press hard-stop & profile lock; continuous ESD monitor; dual-check on flow bench; recipe/gate hardening in MES |
| KPIs @ Run@Rate | FPY 98.6%; Miss-kit PPM 18; Torque Cpk 1.72; Press-depth Cpk 1.82; Leak FA < 0.3% |
| Approvals | Mfg Eng (Owner), Quality (Moderator), Test Eng, Maintenance, IT/MES, Plant Manager |
2) Residual Risk Register (with acceptance) #
Anything not at AP=Low needs explicit status—mitigated, monitored, or formally accepted.
| PFMEA Row ID | Effect (End user) | S | O | D | AP (final) | Residual Risk / Rationale | Accepted By | Date | Monitoring Plan |
|---|---|---|---|---|---|---|---|---|---|
| PF-12-01 | Untested unit ships (bypass) | 10 | 1 | 3 | M | Two-person override + heartbeat watchdog; risk now rare; monitored by weekly audits | Plant Mgr | 03-Sep | Gate override report (0 target) |
| PF-07-02 | Potting voids latent | 7 | 2 | 4 | M | Closed-loop dispense + cure dual-probe; acceptable given field duty; monitor FPY & returns | Quality Dir | 02-Sep | I-MR on mass; monthly tear-down |
If acceptance is required by customer, add customer sign-off box and reference their CSR.
3) Final Process Control Plan (linked to PFMEA) #
Every significant risk must land in the Control Plan with method, frequency, records, and reaction plan. Include the PFMEA Row ID to keep traceability tight.
| PFMEA Row ID | Process Step | Product/Process Characteristic | Method / Gage | Freq / Sample | Records | Reaction Plan |
|---|---|---|---|---|---|---|
| PF-05-01 | OP05 Press-fit | Depth 12.00 ± 0.05 mm (🎯) & signature window | LVDT + press signature (dual-OK) | 100% + SPC (subgroup 5/30 pcs) | MES curves + SPC DB | Stop cell; quarantine last OK lot; verify LVDT; check hard-stop; 8D if trend |
| PF-06-01 | OP06 Seal | Orientation OK; cleanliness class X (🔧) | Vision 100% + particle gate | 100% + hourly clean audit | MES + audit sheet | Rework/replace; cleanroom audit; lot containment if repeat |
| PF-07-01 | OP07 Potting / ESD | Mass ±Δ g; cure profile OK; ESD <100 V (🎯) | Scale + dual-probe logger; ESD monitor | 100% mass; cure per lot; ESD per shift | MES + ESD log | Hold WIP; verify scales/oven/ionizer; restart with OK log |
| PF-09-01 | OP09 Torque | 4.0 ± 0.3 N·m + angle (🎯) | DC tool trace + socket ID | 100% | MES curves | Re-torque; thread inspection; tool audit; cal check |
| PF-12-01 | OP12 EoL | Leak ≤0.5 @1.5 bar (🔧); Flow ≥35 L/min @ 20 kPa (🔺) | Recipe-locked benches + dual-check (flow vs ΔP/RPM) | 100% + daily 2-pt master | MES curves + master logs | Auto-quarantine on master fail; bench maintenance; parameter audit |
Tip: Mirror column names to your customer’s Control Plan format to avoid rework.
4) Traceability & Evidence Map (audit-ready) #
Show where each proof lives—your future self (and the auditor) will thank you.
| Evidence Type | System / Location | Owner | Retention |
|---|---|---|---|
| Unit serialization; test/torque/press curves | MES (Unit Record) | IT/MES | SOP + 15 yrs |
| SPC charts & Cpk reports | SPC DB / Quality share | QE | 3 yrs |
| MSA studies (GR&R, masters) | Metrology drive | Metrology | 3 yrs |
| Calibration & PM logs | CMMS / Calibration system | Maintenance | Per QMS |
| Recipe/gate changes & overrides | MES Audit Log | IT/MES | 3 yrs |
| Training & certification | LMS | HR/Training | Per policy |
| 8D / LL | QMS / LL KB | Quality | Per policy |
5) Lessons Learned (LL) — make it reusable #
| Area | Lesson | Reuse Instruction |
|---|---|---|
| Press-fit | Precision hard-stop + profile lock prevents depth drift | Standardize on PRS-30 profile pack across lines |
| ESD | Continuous monitor with interlock beats manual checks | Make it mandatory for all PCB stations |
| EoL | Dual-check (flow vs ΔP/RPM) cuts false-accept | Add rule to MES recipe template |
| MES Gates | Two-person override + alerts stops “ghost passes” | Roll out to all safety/regulatory gates |
Publish LL to plant knowledge base and link PFMEA row IDs.
6) Change-Control Traceability (tie-ins) #
Map every risk-reducing change to controlled documents.
| Change | Doc ID / WI / Recipe | ECN / CR | Effective Date |
|---|---|---|---|
| Press profile lock & hard-stop shim | WI-OP05-PF-B / PRF-PKG-EWP-R2 | ECN-EWP-134 | 25-Aug |
| Continuous ESD monitor | WI-OP07-ESD-A / MES-ESD-CFG | CR-IT-482 | 28-Aug |
| Dual-check on flow bench | MES-FLOW-RCP-V3 | ECN-TEST-211 | 01-Sep |
| Two-person gate override | MES-GATE-POL-R1 | CR-IT-489 | 30-Aug |
7) PPAP / Audit Pack (submission index) #
Adjust to your customer’s CSR. Below is a practical, compact index.
- Cover & PFMEA Summary (this lesson)
- Process Flow Diagram (PFD) Rev-A
- PFMEA (AIAG-VDA aligned) Rev 1.4
- Process Control Plan (final)
- MSA Studies (GR&R for LVDT, torque, leak, flow; master routines)
- Capability Studies (Cpk: torque, press-depth; stability charts)
- Calibration & PM Evidence (key tools/benches)
- Work Instructions / Photos (critical ops: OP05/06/09/12)
- Traceability & MES Gate Policy (no-scan gate, override controls)
- Action Tracker & Re-ratings (Step 6 before/after)
- Residual Risk Acceptances (signed)
- Lessons Learned Extract (with deployment plan)
Bundle as a single PDF or a structured zip with the above folder names.
8) Release Criteria (Go/No-Go checklist) #
| Criterion | Target | Status |
|---|---|---|
| AP-High open | Zero | ✔ |
| AP-Medium with plan | Dated & approved | ✔ |
| SPC on SCs | In control; Cpk ≥ 1.67 | ✔ |
| MSA | %GRR ≤ 10% (key gages) | ✔ |
| EoL benches | Daily masters pass; dual-check live | ✔ |
| MES gates | Active; override log tested | ✔ |
| Training | All operators certified | ✔ |
| PPAP pack | Indexed & approved | ✔ |
9) What to file on Day-1 of SOP (sustainment) #
- Layered Process Audits (LPA) schedule covering OP05/06/09/12
- Dashboard: FPY, DPMO, AP-H/M count, Cpk for SCs, gate overrides (weekly)
- Trigger rules: Any SPC rule break or master fail → PFMEA/CP review within 24 h
- Quarterly review: Re-open PFMEA with field data, scrap Pareto, and LL updates
✅ Outputs of Step 7 #
- ✅ PFMEA Summary Table and Residual Risk Register signed.
- ✅ Control Plan finalized and linked to PFMEA row IDs.
- ✅ Traceability & Evidence Map established.
- ✅ Lessons Learned published and cross-referenced.
- ✅ PPAP/Audit Pack compiled and indexed.
- ✅ Go/No-Go checklist completed for launch.
⚠️ Common pitfalls (and fast fixes) #
| Pitfall | Fix |
|---|---|
| Control Plan not matching PFMEA | Cross-check by PFMEA Row ID in both docs. |
| Re-ratings without evidence | Attach MSA/SPC/Master snapshots in the pack. |
| Missing gate/audit logs | Export MES audit & override logs to the pack. |
| Lessons learned not deployed | Add owner & due date for each LL rollout. |
🔗 Next #
If you want a final bow on the PFMEA module, I can deliver Lesson 5.8 — Wrap-Up, Metrics & Audit Readiness Pack (optional), or compile all module templates into a clean, shareable zip.
