Statistical tools & concepts (IATF only)
Plain-language summary
Statistical methods are chosen deliberately during planning (APQP/PFMEA stage), included in the control plan — and the people using them actually understand variation, control, capability and over-adjustment.
What the clause is really asking
Determine the appropriate statistical tools during advance quality planning and verify their inclusion in the control plan; ensure basic statistical concepts (variation, control/stability, capability, consequences of over-adjustment) are understood and applied by personnel involved in collecting, analysing and managing statistical data.
What auditors look for
Auditors check the thread: PFMEA/planning shows the tool decision, control plan shows the tool, the operator/technician at the chart can explain what an out-of-control point means and why chasing every point (over-adjustment) makes things worse.
Typical evidence
Planning records showing tool selection; control plans referencing the tools; statistical training records; interview results at the charts.
How to comply — recommendations
Pick your statistical toolbox per characteristic class during APQP and write it into the control plan. Train the floor on the four concepts in plain language — one toolbox talk with a marble-drop demo beats a day of slides.
Common nonconformities
Tools appearing nowhere in planning records; SPC run by people who cannot read their own chart; operators adjusting on every point (over-adjustment institutionalised).
Related clauses
Builds on ISO 9001 9.1.1
Qlause provides interpretive guidance only and is not a substitute for the standard. Refer to your licensed copy of ISO 9001 / IATF 16949 for the authoritative text.