Supplier Scar

Supplier Corrective Action Request (SCAR)

When to use

Use this skill when:

• A supplier NCR requires a formal corrective action (beyond simple return/replacement)
• A supplier has delivered the same non-conformance twice or more
• A non-conformance has caused a production line stoppage, customer complaint, or field failure
• A supplier's quality performance score falls below the defined threshold
• An OEM customer issues a concern that is traced to a sub-supplier
• Preparing a SCAR, evaluating a supplier's 8D response, or conducting an effectiveness review

Prerequisites

• Non-conformance documented (NCR or equivalent) with: part number, description, quantity, measured evidence
• Supplier code, contact name, and corrective action coordinator identified
• SCAR response timeline agreed (typically 24h for D3, 30 days for full 8D)
• Historical data: previous SCARs, PPM trend, quality score for this supplier

Workflow

Step 1 — Escalation criteria: when does an NCR become a SCAR?

Issue a SCAR when any of the following conditions are met:

Do NOT issue a SCAR for every NCR — use NCR + return for minor first-occurrence issues and reserve SCAR for systemic or high-risk situations.

Step 2 — Write the SCAR

The SCAR document must contain:

Header:

• SCAR number (unique, traceable)
• Date issued
• Supplier name, supplier code, contact person
• Issued by (supplier quality engineer name)

Non-conformance description:

• Part number and revision
• Delivery reference (PO number, lot number, delivery note)
• Quantity delivered / quantity non-conforming / % affected
• Defect description in objective-evidence language (measured values vs. specification — not opinions)
• Customer impact (if applicable): production stop, customer complaint, field return
• Reference to the NCR (attach or link)

Response requirements: Specify exactly what the supplier must provide and by when:

Always require TWO root causes: why the defect was produced (occurrence) AND why it was not detected (escape).

Containment verification: State that the supplier must confirm:

• All suspect stock at their facility has been identified and quarantined
• All stock in transit has been recalled or placed on hold
• All stock at your facility has been segregated (include quantity)
• A containment verification plan is in place before any further shipments are accepted

Step 3 — Evaluate the supplier's 8D response

Use the 8D Evaluator methodology (skill: 8d-problem-solving) to review the supplier's response. Focus on the most common SCAR-specific failures:

D3 — Containment:

• Is the containment in PAST TENSE? (If it says "we will inspect going forward" — reject)
• Does it cover all locations (supplier, transit, your facility, customer)?
• Is there a verification result (quantity sorted, quantity rejected, quantity cleared)?

D4 — Root cause:

• Are BOTH causes identified: occurrence (why produced) AND escape (why not caught)?
• Is the root cause supported by evidence, or is it opinion?
• Reject: "human error", "operator oversight", "customer changed specs" — always ask why it was possible
• Verify: if the supplier claims "operator error", ask why the error was not detected by the control plan

D5 — Permanent corrective action:

• Does the PCA directly address the confirmed root cause?
• Is "retrain the operator" the only action? If so, reject — training is not a systemic fix
• Is there a poka-yoke or process change that makes the defect impossible or immediately detectable?

D7 — Systemic prevention:

• Has the PFMEA been updated to reflect the failure mode and new controls?
• Has the Action Priority (AP) been revised in the PFMEA after verified corrective action? The revised AP must be lower than the original or documented with justification — AP revision is only valid after D6 effectiveness is confirmed, not at planning stage.
• Has the Control Plan been updated?
• Have Work Instructions been updated?
• Has horizontal deployment been considered (same process at other lines/plants)?

D6 — Verification:

• Is there production data showing the PCA is effective?
• What quantity was run? Over what period?
• What is the measured improvement (before/after comparison)?

Step 4 — Issue a SCAR response rejection

If the supplier's 8D response does not meet the gate criteria, reject it formally:

Rejection notice must specify:

• Which discipline(s) failed and why (specific, not generic)
• What is required in the revised response
• Revised deadline for resubmission

Do not accept a response that:

• Has no evidence of D3 completion (only a plan)
• States "human error" as the final root cause without systemic analysis
• Lists only training as the PCA
• Has no PFMEA or CP update in D7
• Shows no production data in D6

Step 5 — Effectiveness verification

30–90 days after PCA implementation, verify that the corrective action is effective:

Methods:

• Monitor incoming quality data: zero recurrence of the same defect in the next X deliveries
• Review updated PFMEA and Control Plan (request current revision, verify D4 failure mode is addressed)
• On-site verification: audit the specific process step where the defect occurred (use VDA 6.3 P6 questions for that step)
• Request production data showing Cpk improvement on the relevant characteristic

Close the SCAR when:

• Zero recurrence of the same non-conformance for the agreed monitoring period (typically 3–6 months)
• Updated PFMEA, CP, and WI documents received and verified
• Effectiveness data reviewed and accepted

If recurrence occurs during monitoring:

• Escalate to supplier management (not just quality coordinator)
• Consider: production stop, new supplier qualification, customer notification
• Issue a new SCAR referencing the previous one as evidence of systemic failure

Step 6 — Supplier performance tracking

Link every SCAR to the supplier's quality performance record:

• PPM trend (Parts Per Million non-conforming)
• SCAR open count and average response time
• Closure rate (closed on time vs. overdue)
• Recurrence rate (same defect within 12 months of a previous SCAR)

Suppliers with repeated SCARs or recurrences should be placed on:

• Controlled shipping — every delivery inspected before acceptance (in automotive: CS1 = supplier-managed 100% sort; CS2 = customer-managed sort at supplier's cost)
• Supplier improvement plan — formal APQP-style corrective programme
• Qualification review — potential re-qualification or replacement

Warranty cost recovery / debit note risk: In automotive OEM supply chains, SCARs that result in field failures or warranty claims can trigger financial recovery. The OEM issues a warranty debit note to the Tier 1, who cascades it to the responsible sub-supplier via SCAR. Each SCAR must therefore document whether the non-conformance caused any field or warranty cost — this determines whether cost recovery applies. A SCAR without this assessment is incomplete for OEM reporting purposes. If warranty cost recovery is raised, escalate immediately to commercial and legal before responding to the OEM.

Validation criteria

A SCAR is closed when:

• Full 8D submitted with both root causes confirmed (occurrence AND escape)
• Permanent corrective action verified with production data (D6)
• PFMEA, Control Plan, and Work Instructions updated and received (D7)
• No recurrence of the same non-conformance during the agreed monitoring period
• Closure signed off by Supplier Quality Engineer and documented in the supplier record

Common mistakes

• Issuing a SCAR for every NCR — dilutes the severity signal; suppliers stop taking SCARs seriously
• Accepting a D3 response that is a plan ("we will inspect") rather than a completed action
• Closing the SCAR when the 8D is submitted rather than when effectiveness is verified
• Accepting "human error" or "operator training" without requiring a systemic root cause
• Not updating the supplier performance record — next engineer doesn't know the history
• Allowing the SCAR to stay open indefinitely with no escalation — sets the precedent that deadlines are negotiable

Output Format

At the start of each use, ask the user:

"How would you like to receive the output? A — Structured Markdown (formatted tables and sections, ready to copy) B — Plain tables (simplified structure for Excel or Word) C — Narrative report (flowing text for a formal document or email)

Default: A."

Adapt all output sections to the chosen format. If the platform or session context already defines a format preference, skip this question.

Changelog