Supplier Corrective Action Request (SCAR): How to Issue and Close One

A Supplier Corrective Action Request (SCAR) is the formal request a customer issues to a supplier when a confirmed defect requires investigation and a permanent fix. It is the supplier-facing equivalent of an internal corrective action — same logic, same evidence requirements, but the work is performed by the supplier and verified by the customer. See the broader supplier quality guide for where SCARs fit in the program.

What a SCAR is and what it isn't

A SCAR is a request for corrective action, not a complaint, a debit memo, or a credit-claim form. The deliverable is a closed corrective action with verified effectiveness. Commercial recovery (chargebacks, sort costs, scrap reimbursement) usually rides alongside the SCAR but is tracked separately so quality activity does not get confused with finance.

A SCAR is also not the right tool for every issue. Single-unit defects with no pattern, cosmetic issues at low volume, or documentation typos rarely justify the supplier's investment to investigate. Most programs reserve SCARs for repeatable defects, safety-critical characteristics, audit nonconformances, or any escape to the end customer.

When to issue a SCAR

The triggers most programs use:

• Repeat defect — same failure mode on two or more lots within a defined window.
• Single defect on a safety- or function-critical characteristic.
• Any escape to the end customer that traces back to a supplier-caused cause.
• Audit nonconformance (system, process, or product).
• Failed PPAP or FAI element that the supplier did not self-identify.
• PPM threshold breach in the supplier scorecard.

Every SCAR should reference the source NCR or audit finding so the audit trail is intact. A SCAR with no upstream record is hard to defend during surveillance.

The 8-stage SCAR process

Most programs map the SCAR to the 8D structure because the major automotive and aerospace OEMs require it. The stages:

1. Issue — customer sends the SCAR with problem statement, evidence, severity, and required response dates.
2. Acknowledge — supplier acknowledges within 24 hours.
3. Contain — supplier returns containment scope (lots, locations, quantities) within 48 hours.
4. Investigate — supplier returns root cause (occurrence and detection) within 14 days.
5. Plan — supplier returns full corrective action plan within 30 days.
6. Implement — supplier executes the plan and submits evidence.
7. Verify — customer confirms implementation; supplier supports an effectiveness check at 60-90 days.
8. Close — SCAR closes on demonstrated effectiveness, with read-across recorded.

Response timeline customers expect

The default automotive 8D timeline (8-24-14-30-60) is the de facto standard across most supplier quality programs:

• 8 hours — supplier acknowledgement and team formed.
• 24-48 hours — containment in place with defined scope.
• 14 days — root cause analysis complete.
• 30 days — corrective action plan submitted.
• 60-90 days — effectiveness verified.

Aerospace customers often allow longer windows on the investigation side but tighter containment; medical device customers typically follow ISO 13485 risk-based response with no fixed clock. Whatever the dates, they should be set in the SCAR itself, not left implicit.

Required fields on a SCAR

• SCAR number and revision.
• Customer and supplier identifiers, including contact owners on both sides.
• Part number, revision, lot or serial numbers affected.
• Source NCR or audit finding reference.
• Problem statement — what, where, when, how many, how detected.
• Evidence — photos, measurements, failed samples returned or available.
• Severity classification (critical, major, minor) — drives the response window.
• Required response dates for each 8D stage.
• Containment expectation (specific lots, customer and supplier locations).
• Required format for the response (8D, supplier-specific form, or attached template).

Evaluating the supplier's response

First-pass acceptance is one of the most useful supplier quality metrics. A response should be rejected and reissued if any of the following are true:

• The root cause is a restated symptom ("operator error," "wrong part used," "out of spec").
• Only the occurrence cause is addressed; the detection cause is missing or generic.
• The corrective action plan is entirely training and procedure updates with no engineering control.
• Containment scope is undefined or appears not to cover all suspect inventory.
• Owners are listed as departments rather than named individuals.
• Effectiveness criteria are vague ("monitor for recurrence") or have no measurable threshold.
• Read-across to similar parts or processes is missing.

Rejecting weak responses is the only way to keep the SCAR process meaningful. Accepting them once teaches the supplier that the bar is lower than the SCAR template implies.

Escalation

Most programs run a three-level escalation:

1. Level 1 — standard SCAR managed by the supplier quality engineer.
2. Level 2 — repeat or unresolved SCARs trigger a managed quality plan, on-site visit, and increased inspection at the customer.
3. Level 3 — controlled shipping (CS-1 in automotive: 100% sort by supplier with second-side verification), business hold, and potential re-sourcing.

Escalation thresholds (e.g. three Level 1 SCARs in 6 months, or one critical escape) should be defined in the supplier quality agreement, not invented at the time of escalation. See the supplier scorecard guide for how SCAR performance feeds the tiering.

Examples

Example 1: Bent connector pins (electronics)

Three lots rejected at incoming for bent pins. SCAR issued with photos and measurement data. Supplier returned containment within 48 hours, identified that a packaging tray change had not been communicated through their PPAP gate, and reverted the tray. Corrective action added a controlled characteristic to the supplier quality agreement. Effectiveness verified over 8 lots with zero rejects.

Example 2: Surface finish out of spec (aerospace machining)

Customer found surface roughness above the print limit on one of fifty parts during incoming AS9102 re-verification. SCAR issued at severity major. Supplier traced the cause to a new operator running the part with the wrong feed override; detection cause was the in-process surface check being sampling-based. Corrective action added in-line surface measurement and a tool-program lockout on feed override. Read-across to two similar parts on the same machine.

Example 3: Wrong material certification (medical device)

Supplier shipped lot with material certs from the previous heat. SCAR escalated to Level 2 because of the regulated nature of the material. Supplier root cause traced to a manual cert-matching step and a barcode that did not include the heat number. Corrective action added barcode scanning of the heat number at packaging and an ERP rule that blocks shipment when the cert and heat do not match.

For more worked examples and the underlying corrective action structure, see corrective action examples. For the template that backs the SCAR, see the SCAR template guide.