How to write a SCAR (supplier corrective action request)

Contain your side before you send it

The SCAR protects the next shipment. Your own plant needs protecting today. Quarantine and tag the suspect material, check work in process and finished goods that contain the part, and decide the disposition: sort, return, scrap or rework. Use a part as-is only under a formal, approved deviation. If suspect parts may have reached your customer, tell them now, not when the SCAR closes.

What to put in the SCAR

1. Identify the part and the lot

   Your part number and the supplier’s, the purchase order, the lot, heat or date code, the quantity received and the quantity found nonconforming. Give the SCAR a number of its own.

2. State the requirement and what you found

   Name the drawing or specification characteristic, the tolerance and the measured values. Attach photos, the inspection record and a sample if you can. Say where it was found: at receiving, in process or at your customer.

3. Describe the impact

   Line stops, sort hours, scrap, rework, premium freight and any effect on your customer. Impact is what decides how hard you push and how fast.

4. Say what you have already done

   Your containment and the disposition of the suspect parts: sorted, returned, scrapped, reworked, or used under an approved deviation.

5. State what you need back, and by when

   Containment at their site, covering their stock, work in process and anything in transit. Then root cause, corrective actions and evidence. Set the timing in your supplier agreement or supplier manual. Ask for containment first, then root cause and planned actions, then evidence the fix works.

6. Name the response format

   If you want the answer as an 8D, or on your own form, say so in the request. A response in a format you didn’t ask for is the supplier’s choice, not yours.

What to demand in the response

• Two root causes, with evidence. Why it was made, and why it escaped their plant. A three-legged answer adds why their system allowed it. Ask for the data or the trial that proves each cause, not a sentence.
• Containment that reaches every location. Their finished goods, work in process and in transit, plus how certified shipments will be marked so your receiving can see the clean break.
• Actions that remove the cause. "Retrained the operator" and "added 100% inspection" are not permanent corrective actions on their own. Look for error-proofing, process changes and detection that can actually catch it.
• Their documents updated. Their PFMEA, Control Plan and work instructions should change with the fix. Ask for the revised pages.

How to verify and close it

• Check the first certified shipments yourself. Increase receiving inspection on the characteristic for a set number of lots, and record the results against the SCAR number.
• Look at the history, not one lot. Your incoming part history and scorecard should show the defect gone over time, not just on the first shipment after the fix.
• Go and see when the risk is high. For safety or special characteristics, or a repeat problem, verify the actions at the supplier’s site.
• Close it with evidence, then score it. Close only when the actions are verified and your data agrees. Record the result on the supplier’s scorecard so repeat problems are visible.

The mistakes that weaken a SCAR

• A vague description. "Parts out of spec" gives the supplier nothing to work with. Name the characteristic, the tolerance and the measured values.
• No deadline. A SCAR without dates is a suggestion.
• Accepting containment as the fix. Sorting protects you this week. It does not stop the next lot.
• Closing on the supplier’s word. The response is a plan. Your receiving data is the proof.
• Issuing and forgetting. Track every open SCAR with an owner and a due date, and chase it.
• Skipping your own print. If the drawing or specification was unclear, fix it on your side too, or the next SCAR is on you.

Where IATF 16949 fits

IATF 16949 doesn’t name the SCAR, but it expects you to monitor supplier performance, including delivered product quality and the disruptions suppliers cause you (clause 8.4.2.4), to develop suppliers based on that performance (8.4.2.5), and to run a problem-solving process with containment, root cause, corrective action and verified effectiveness (10.2.3). Your customer-specific requirements may add rules for how supplier problems are escalated and reported.

Clause numbers refer to IATF 16949:2016. Your customer’s requirements and your supplier manual come first.