Monitoring & measurement of manufacturing processes (IATF only)
Plain-language summary
Prove your manufacturing processes can do the job and stay capable: process studies on new processes, capability maintained as the control plan specifies, and the documented reaction plan executed when capability or stability slips — including 100% containment and customer notification when required.
What the clause is really asking
Perform process studies on new manufacturing processes to verify capability (inputs to production approval); maintain capability/performance per control plan requirements; verify process flow/control plan/instruction adherence; when unstable or non-capable: apply the reaction plan, contain (100% inspection as appropriate), and implement a corrective action plan with timing — informing the customer where their CSRs require it. Significant events (tool change, repair) should trigger verification, with dates recorded.
What auditors look for
Auditors pick a special characteristic with an SPC chart: capability current and meeting the control plan target? Out-of-control points — was the reaction plan followed, evidenced, signed? After last month's machine rebuild, where is the re-verification? CSR notification rules known and applied?
Typical evidence
Initial process studies (Cp/Cpk/Pp/Ppk); ongoing SPC/capability data; reaction plan execution records; re-verification after significant events; customer notifications.
How to comply — recommendations
Run capability honestly on the characteristics that matter (control plan ones), not a wall of charts for show. Train operators on the reaction plan steps — the chart is only as good as the response to it. Log every significant process event with its re-verification date.
Common nonconformities
Charts maintained but out-of-control points ignored; capability below target with no corrective plan; reaction plans existing only on paper; no re-verification after tooling repairs.
Related clauses
Builds on ISO 9001 9.1.1; links IATF 8.5.1.1, SPC core tool
In the book
Chapter 9 — Evaluation — Reading Your Own Instruments treats this clause family in full: what it is really asking, what auditors look for, the evidence that satisfies, how to make it work on a real floor, and where companies stumble. This IATF requirement is covered in the Automotive Edition, in the same six blocks as the ISO clause around it.
Resources for this clause
- ArticleControl charts explained: telling signal from noise
- ArticleCp vs Cpk vs Ppk: process capability without the confusion
- ArticleMSA and Gage R&R explained: type 1 studies, ANOVA vs average and range, %GRR vs %tolerance, ndc and attribute agreement
- Toolkit · $29SPC Control Chart ToolkitPick the right tab, fill the yellow cells, and watch control limits and charts calculate live — no SPC maths, no macros, no setup.
- Free downloadCpk CalculatorPaste your measurements, get Cp, Cpk and predicted yield instantly — prove the process is capable.
- Free masterclass · ~18 minControl Charts MasterclassStatistical process control in plain English — common vs special cause, choosing and building the right chart (X̄-R, X̄-S, I-MR, p/np/c/u), reading the signals, and proving capability with Cp/Cpk.
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