Special characteristics (IATF only)
Plain-language summary
Identify special characteristics through a defined process — from risk analysis, customer designations and your own knowledge — and carry them visibly through every document: drawings, FMEA, control plan, work instructions.
What the clause is really asking
A documented process must establish special characteristics (customer-designated plus those from your own risk analysis), include them in the control plan and FMEA with the appropriate markings, and apply customer-specified definitions and symbols where they exist.
What auditors look for
Auditors run the correlation check: special characteristics consistent across drawing, PFMEA, control plan and instructions, with the right symbols, and controls genuinely tighter at those steps (capability studies, error-proofing, increased frequency).
Typical evidence
Special characteristics identification procedure; correlation matrix; FMEA/control plan markings; capability evidence on SCs.
How to comply — recommendations
Maintain one SC correlation matrix per part and make it a PPAP document. Any document change touching an SC triggers a matrix check — one rule that prevents the most common automotive audit finding.
Common nonconformities
SC marked in FMEA but not control plan (or vice versa); no process for self-identified SCs; SCs treated identically to standard characteristics in practice.
Related clauses
Builds on ISO 9001 8.3.3; links IATF 8.2.3.1.2
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.