The Production Part Approval Process (PPAP) shows a customer that you understand every requirement for a part and that your production process makes it consistently, at the quoted rate. The AIAG PPAP manual (4th edition) defines 18 elements and five submission levels. Most confusion comes from mixing up two questions: which elements you must complete (all that apply, at every level) and which you must submit (it depends on the level).
The five levels
| Level | What the customer receives |
|---|---|
| Level 1 | The part submission warrant only (and an appearance approval report if the part has appearance items) |
| Level 2 | The warrant with product samples and limited supporting data |
| Level 3 | The warrant with product samples and complete supporting data. The default when the customer does not specify a level |
| Level 4 | The warrant and whatever else the customer defines |
| Level 5 | The warrant with product samples and complete supporting data reviewed at your manufacturing site |
The customer chooses the level, usually on the purchase order or in their supplier quality manual. At level 5 nothing extra is mailed: the customer reviews everything at your site.
The 18 elements, and when each is submitted
S = submit to the customer and keep a copy. R = keep at your site and make available on request. * = the customer decides. At every level you complete every element that applies to the part; the level only changes what you send.
| Element | L1 | L2 | L3 | L4 | L5 |
|---|---|---|---|---|---|
| 1. Design records | R | S | S | * | R |
| 2. Engineering change documents | R | S | S | * | R |
| 3. Customer engineering approval | R | R | S | * | R |
| 4. Design FMEA | R | R | S | * | R |
| 5. Process flow diagram | R | R | S | * | R |
| 6. Process FMEA | R | R | S | * | R |
| 7. Control plan | R | R | S | * | R |
| 8. Measurement system analysis | R | R | S | * | R |
| 9. Dimensional results | R | S | S | * | R |
| 10. Material and performance test results | R | S | S | * | R |
| 11. Initial process studies | R | R | S | * | R |
| 12. Qualified laboratory documentation | R | S | S | * | R |
| 13. Appearance approval report | S | S | S | * | R |
| 14. Sample production parts | R | S | S | * | R |
| 15. Master sample | R | R | R | * | R |
| 16. Checking aids | R | R | R | * | R |
| 17. Customer-specific requirements | R | R | S | * | R |
| 18. Part submission warrant (PSW) | S | S | S | * | R |
What each element is
- Design records: The drawing, specifications and any customer-owned design data for the part
- Engineering change documents: Changes not yet on the drawing but already authorized
- Customer engineering approval: Evidence the customer's engineering approved, when required
- Design FMEA: Only if you are responsible for the design
- Process flow diagram: Every step from receiving to shipping, including rework
- Process FMEA: Risks in each process step and the controls for them
- Control plan: How each characteristic is controlled and checked in production
- Measurement system analysis: Gage R&R and other studies for the gages in the control plan
- Dimensional results: Every dimension on the drawing measured on the sample parts
- Material and performance test results: Material certifications and any functional or performance tests
- Initial process studies: Capability (for example Ppk) on the special characteristics
- Qualified laboratory documentation: Scope and accreditation of the labs that did the testing
- Appearance approval report: Only for parts with appearance requirements
- Sample production parts: Parts from the significant production run
- Master sample: A retained sample signed off with the customer
- Checking aids: Fixtures and gages made for the part
- Customer-specific requirements: Records for any extra requirements the customer sets
- Part submission warrant (PSW): The summary form that declares the part meets every requirement
Elements that do not apply, such as a design FMEA when the customer owns the design, are marked not applicable rather than left out silently. Your customer can also waive an element; keep the waiver with the package.
What triggers a PPAP
A new part needs a PPAP before the first production shipment. After that, a new submission is usually required when something changes that could affect the part, for example:
- An engineering change to the drawing, specification or material
- New, replacement or refurbished tooling, or tooling moved to another plant
- A change of process, method or production location
- A change of sub-supplier or material source
- Production that has been inactive for 12 months or more
- Correcting a discrepancy on an earlier submission
Your customer's requirements decide which changes need a full submission, which need only notification, and which need their approval first. When in doubt, ask before you change, not after.
The part submission warrant
The PSW is one page that identifies the part and revision, the reason for submission, the level and the results, and is signed by an authorized person at the supplier. Signing it declares that the samples represent the production process and meet every drawing and specification requirement. One warrant is normally submitted per part number unless the customer agrees otherwise.
Approval
The customer approves the PPAP, grants interim approval for a limited time or quantity while an open item is fixed, or rejects it. Production shipments need full or interim approval. A rejected package goes back for correction and is submitted again.
PPAP in aerospace
Aerospace uses AS9145, which covers advanced product quality planning and PPAP for aviation, space and defense. Its PPAP requirements overlap with the AIAG elements and include the AS9102 first article inspection (see our guide to AS9102 Form 3). Follow your customer's requirements, which often add their own forms.
Common reasons PPAPs are rejected
- Dimensional results that miss drawing notes or use "OK" instead of measured values
- A control plan that does not match the process flow and PFMEA
- Measurement system analysis missing for gages in the control plan
- Capability studies on too few parts, or not on the special characteristics
- A warrant signed before the evidence was complete
Requesting PPAPs from your own suppliers? Our guide to supplier PPAP covers choosing the level and reviewing each element.
In FactoryQA a new PPAP lists the 18 AIAG elements and sets each to Submit or Retain from the level you pick. You attach evidence or link the ballooning, flow chart, PFMEA and control plan, generate the PSW as a Word document, and record approval, interim approval or rejection. Suppliers upload their elements in a portal without an account. See Quality Plans.
Frequently asked questions
What is the default PPAP level?
Level 3: the warrant, product samples and complete supporting data. It applies when the customer does not specify another level.
What is the difference between submit and retain?
Submitted elements are sent to the customer. Retained elements are completed and kept at your site, ready for the customer to see on request. At every level you complete all elements that apply.
How many PPAP elements are there?
Eighteen in the AIAG PPAP manual, from design records to the part submission warrant. Some do not apply to every part, such as the design FMEA when the customer owns the design.
What is interim approval?
Approval to ship for a limited time or quantity while an open item, such as a capability study, is completed. It ends with full approval or a rejection.
Does aerospace use PPAP?
Yes, through AS9145, which defines APQP and PPAP requirements for aviation, space and defense, including the AS9102 first article inspection.