Before the elements: three questions
- Which submission level and which customer-specific requirements apply? Ask in writing.
- Was the production run on production tooling, gauges, material and operators, and is it documented?
- Is everything at the same drawing revision?
The 18 elements and what to check
| # | Element | Check before sending |
|---|---|---|
| 1 | Design records | Latest drawing revision, every characteristic ballooned, same revision as the PSW. |
| 2 | Engineering change documents | Every open change in the package, signed, matching the drawing. |
| 3 | Customer engineering approval | Only if the customer requires it; attach the evidence. |
| 4 | Design FMEA | If you are design-responsible. Special characteristics line up with the drawing. |
| 5 | Process flow diagram | Every step incl. rework, inspection and storage; same step numbers as the PFMEA. |
| 6 | Process FMEA | Steps match the flow; ratings and actions are current, not copied from a sister part. |
| 7 | Control plan | Each special characteristic has a method, sample size, frequency and reaction plan. |
| 8 | MSA studies | Gage R&R for gauges in the control plan; attribute study for go/no-go and visual checks. |
| 9 | Dimensional results | Every drawing characteristic, actual values, per cavity or process stream. |
| 10 | Material and performance test results | Lab name, standard, date, result vs requirement. |
| 11 | Initial process studies | Ppk (or Cpk) for special characteristics, with the run data and the σ basis stated. |
| 12 | Qualified laboratory documentation | Scope and accreditation of every lab used. |
| 13 | Appearance approval report | Only for appearance items, if required. |
| 14 | Sample production parts | From the production run, labelled and traceable. |
| 15 | Master sample | Kept, identified, and its storage is known. |
| 16 | Checking aids | List, calibration status, and MSA where applicable. |
| 17 | Customer-specific requirements | Each CSR item answered, not just referenced. |
| 18 | Part submission warrant (PSW) | Weights, revision, reason for submission and level all filled; signed. |
Element names are shortened from the AIAG PPAP list; check descriptions are our own. Your customer's manual overrides.
Worked count: dimensional results for a 4-cavity tool
A moulded cover has 42 ballooned characteristics and a 4-cavity tool. If the customer wants one fully measured part per cavity, the dimensional results hold 4 × 42 = 168 measured values. If the package shows 42, three cavities are missing. Count lines before you send.
Same tool, initial process study on 3 special characteristics: each needs its own Ppk, per cavity if the cavities are separate process streams, so up to 3 × 4 = 12 indices. A single pooled Ppk across cavities can hide one bad cavity. A characteristic with Ppk 1.52 falls in the 1.33 to 1.67 band: flag it and agree a plan with the customer before sending, rather than hoping nobody notices. Check values with the Cpk / Ppk calculator; the Cpk vs Ppk guide explains which σ to use.
Consistency checks (do these last)
- Process flow step numbers = PFMEA step numbers = control plan step numbers.
- Every special characteristic on the drawing appears in PFMEA, control plan, and the capability study.
- Every gauge in the control plan has an MSA result (see Gage R&R basics).
- PSW part weight, revision and submission level match the package.
- Dates are in order: production run before studies, studies before PSW signature.
When PPAP follows an 8D
A permanent corrective action that changes the process (new tool, new supplier, new process step) usually needs customer notification and often a resubmission. Check this in D5/D7, before implementation, not after the parts ship. See PFMEA and control plan update after an 8D and IATF 16949 8D requirements.
FAQ
- Which PPAP level should I submit?
- The customer decides. Level 3 (warrant, samples and complete supporting data) is the usual default when nothing is specified. Levels 1 and 2 send less; level 4 is defined by the customer; level 5 means the data is reviewed at your site.
- How big must the production run be?
- Unless the customer says otherwise, the AIAG PPAP manual describes a significant production run of 1 to 8 hours of production with at least 300 consecutive parts, on production tooling, gauges, process, material and operators.
- What Ppk do I need in the initial process study?
- A common acceptance scheme: at least 1.67 meets the requirement, 1.33 to 1.67 may be acceptable with customer agreement, below 1.33 does not. Use the limits in your customer's requirements. See the Cpk vs Ppk guide for which σ to use.
- What are common reasons a PPAP is sent back?
- Mismatches between documents: drawing revision vs PSW, process steps vs PFMEA vs control plan, characteristics on the drawing missing from the dimensional results. Check consistency before content.