What is PPAP?
8 min read · Updated 2026-08-17
The Production Part Approval Process is how a supplier demonstrates, before shipping production volume, that it can make a part to specification and keep making it to specification.
The logic is simple. A customer cannot inspect trust into a supply chain, so instead of checking every part they check the evidence that the process is capable. PPAP is the standard shape of that evidence.
What is in a submission
The element list varies by customer, but the core is consistent:
- Design record — the drawing or model the part is made to.
- Engineering change documents — any authorised changes to that record.
- Customer engineering approval — where the customer requires it.
- DFMEA — design risk analysis, where the supplier is design-responsible.
- Process flow diagram — the operation sequence.
- PFMEA — process risk analysis.
- Control plan — what is controlled, how, and how often.
- Measurement system analysis — evidence the gauges can tell good from bad.
- Dimensional results — measured results against the drawing.
- Material and performance test results — that the material and the part perform.
- Initial process studies — capability on the significant characteristics.
- Qualified laboratory documentation — that testing was done somewhere competent.
- Appearance approval report — where appearance is specified.
- Sample product and master sample — actual parts.
- Checking aids — fixtures and gauges specific to the part.
- Customer-specific requirements — whatever else that customer asks for.
- Part Submission Warrant — the signed declaration that ties it together.
How submission levels work
This is the part most often misunderstood. The levels do not change what you have to do — they change what you have to send. At every level you are expected to have completed the work and to retain the records. The level determines how much of it travels to the customer:
| Level | What it means in practice |
|---|---|
| 1 | Warrant only submitted; everything else retained. |
| 2 | Warrant with samples and limited supporting data. |
| 3 | Warrant with samples and complete supporting data. The most common default. |
| 4 | Warrant plus whatever the customer specifically defines. |
| 5 | Warrant with samples and complete data, reviewed at your site. |
The practical consequence: "we are only level 1, so we do not need the capability study" is a misreading. You need the study. You are simply not posting it.
When PPAP is required
At a new part, and then again on change. A new part or product, a correction of a previous discrepancy, a change in design, specification or material — and, importantly, a range of process changes that suppliers frequently underestimate: new or modified tooling, tooling moved to a different location, a change of subcontractor for a component or service, tooling that has been inactive for an extended period, or a change in test method.
Why PPAP is painful, and what actually causes it
Rarely the documents themselves — most quality teams can produce a control plan. Two things cause the pain.
Every customer wants a different version of the same thing. Different required elements, different naming, different order, different approval signatures. That knowledge tends to live in one experienced person’s memory, and the process collapses when they are on leave.
The evidence is scattered. The PFMEA is in one folder, the capability study is in an engineer’s email, the MSA is on a shared drive under a filename with a typo. Assembling the package becomes an archaeology exercise performed under deadline.
Both are structural, and both are solvable by holding customer requirements as configuration against the customer, and by linking each element to the record that satisfies it rather than to a copy of it.
Reading further
The AIAG PPAP manual is the authoritative reference and is licensed material. Your customer’s own customer-specific requirements document sits on top of it and usually overrides it — read that one carefully.