Supplier corrective action process flowchart (SCAR, issue to closure)
Supplier corrective action process flowchart (SCAR): screen the failure, issue with deadlines, contain stock on both sides, prove root cause and escape point, verify effectiveness over agreed lots, then close or escalate.
How it works
Rename the lanes to your own structure
Replace Detecting function, Supplier quality, Supplier, Purchasing and Quality manager with the roles you actually have. Detecting function is deliberately generic because the trigger arrives from goods-in, from the line and from the field, and all three should enter the same process rather than three parallel ones. If one supplier quality engineer both issues the SCAR and reviews the response, keep that lane single rather than inventing a reviewer who does not exist. Do not delete the Purchasing lane even on a small site: somebody has to own the commercial consequence, and if nobody does, the escalation branch is decoration.
Write the trigger test as figures and a history rule
"Significant or a repeat failure?" is inert until you attach numbers to it. Set a cost-of-poor-quality threshold, list the characteristics that escalate regardless of cost — safety, regulatory, form-fit-function, anything the customer specified — and define repeat as the same failure mode from the same supplier and part within a rolling period. Then decide who may raise a SCAR without asking permission. If only the quality manager can, expect an inspector to write a rejection note instead, and expect the trend that would have justified the SCAR to disappear with it.
Fix the response deadlines and who may extend them
Give the SCAR four clocks rather than one date: acknowledgement, containment, root cause with a proposed plan, and effectiveness verification. One working day, twenty-four to forty-eight hours, ten to fifteen working days and an agreed number of lots is the usual shape, and it is roughly what an 8D response form is built around. The figures matter less than putting them in the supplier quality agreement, so that they are contractual rather than aspirational. Name the person who may grant an extension and record it on the SCAR when they do — an untracked extension is how a ten-day investigation quietly becomes a three-month one.
Say what an acceptable plan must contain
Turn "Plan accepted?" into a checklist your reviewers apply the same way each time. An acceptable plan separates the correction from the corrective action, answers both the occurrence and the escape, names an owner and a date against every action, states a cut-in date and how cut-in stock will be marked or labelled, and says which other parts, lines and sites the same cause reaches. Add a rule that retraining is never sufficient on its own: it is the most common single-line answer on a returned 8D and the least durable.
Set the verification window in lots, and settle the cost recovery
Decide at plan acceptance how effectiveness will be proved: how many consecutive deliveries, what sample size on the affected characteristic, who inspects them, and what result counts as a failure. Express the window in lots rather than days so a low-volume supplier is genuinely tested. While you are there, settle the cost recovery — sorting hours, rework, premium freight, scrap — because a SCAR that never mentions money is the one a supplier deprioritises, and the debit note is far easier to raise while the evidence is still fresh.
Walk it through with the supplier, then publish a version
Send the finished chart to two or three of your suppliers before you adopt it and ask which steps they cannot meet and why. The answers usually improve the deadlines and the evidence pack more than another internal review would. Then walk it through with your inspectors, the supplier quality engineer and the buyer who will have to make the escalation call, correct it to what they will genuinely do, and publish that revision while keeping the earlier ones, so anyone opening it later can tell which version they are reading.
Frequently asked questions
What are the steps in a supplier corrective action (SCAR) process?
Quarantine the affected stock and report the nonconformity with evidence; decide whether it is significant or a repeat and therefore warrants a SCAR at all; issue the request with the full evidence pack and separate response deadlines; get the supplier to acknowledge it and name a response team; contain affected stock at the supplier, in transit, at your site and, if it has gone that far, at your customers; establish the root cause of the occurrence and, separately, the escape point where the supplier's own controls failed to detect it; propose and accept a corrective action plan; implement it with a cut-in date and marked stock; update the control plan and read the finding across to similar parts; verify effectiveness over an agreed number of lots; then close it, or take the escalation route — re-investigation, an on-site process audit or de-listing. That order maps onto the 8D discipline, which is what most supplier response forms are built from, and the two steps that get skipped are the escape point and the verification window.
What is the difference between a SCAR and a CAPA?
A CAPA is internal: you raise it against your own process, your own people investigate it, your own management approves the plan, and you verify the fix by going to look. A SCAR crosses a company boundary, and that single fact changes the mechanics. You cannot direct another company's investigation, choose their method, read their process data or walk their line without a contractual right to do so, which is why the request has to carry enough evidence for them to work from and the deadlines have to sit in the supplier agreement rather than in your procedure. Verification changes too: you cannot watch the fix being made, so effectiveness is proved by inspecting the deliveries that follow the cut-in date. And when the response is poor, your remedy is commercial rather than managerial — conditional status, an audit, cost recovery, de-listing. The internal version is at /templates/capa-process, and a supplier failure that reached your customer will usually need both, because it is also a nonconformity in your own system.
What is an escape point, and why does it matter?
The occurrence root cause explains why the defect was created. The escape point explains why it left the supplier's site instead of being caught. They are different questions with different answers and, almost always, different fixes: a tool that wore out early is an occurrence cause, and a final inspection that sampled one part an hour is why nobody noticed. The 8D discipline asks for both, and the escape half is the one most often missing from a returned form, because a sentence about changing the tool-change frequency reads like a complete answer. It matters commercially as well as technically: if only the occurrence cause is fixed, the same detection gap is still in place for the next failure mode out of that process. In this chart "Establish the escape point" is a step of its own, and the gate that follows it, "Root cause and escape point proven?", is written so that an analysis answering only one of the two is returned rather than accepted.
How long should a supplier be given to respond to a SCAR?
Set separate clocks for separate deliverables rather than one date for the whole thing. Acknowledgement and the name of a response owner within one working day is normal, because it costs the supplier nothing and tells you immediately whether the request reached anybody at all. Containment within twenty-four to forty-eight hours, because it is the part that stops the problem growing while everything else is still unknown, and it is the deadline worth stating first. Root cause and a proposed corrective action plan within ten to fifteen working days, scaled to the complexity of the failure rather than to your impatience — a metallurgical investigation is not a ten-day job, and pretending otherwise produces a guess rather than a cause. Effectiveness verification is not a date at all but a number of lots. Whatever figures you choose, put them in the supplier quality agreement so they are contractual, and name who in your organisation may grant an extension. Deadlines that live only in your own procedure are, from the supplier's side of the boundary, a preference.
What should happen when a supplier's corrective action does not work?
Treat an ineffective supplier corrective action as information rather than as an administrative failure. In most cases it means the cause was wrong, not that the implementation was sloppy. In this chart the Not effective side of the verification gate neither closes the record nor quietly reopens it: it goes to "Escalation route?", a decision somebody has to own, with three ways out. Re-investigate sends the analysis back with what you now know, including the fact that the first cause has been ruled out. Audit puts you on the supplier's site to look at the process yourself. De-list starts resourcing the part. Which applies should depend on the severity, the number of previous SCARs and how easily the part can be moved. The commercial measures that usually travel with the first two — conditional status so no new business is placed, and charging back sorting, rework, premium freight and scrap — sit with Purchasing, and the decision should be recorded with a date and a name against it. A SCAR that recurred twice and led to nothing is the finding an auditor picks up, and the pattern belongs in the periodic scorecard at /templates/supplier-evaluation-process.