PPAP for Wire Harnesses: Levels & Elements

What PPAP is

PPAP is published by the Automotive Industry Action Group (AIAG) as one of the core tools used with the IATF 16949 quality management standard. It defines the evidence a supplier provides before production shipments are approved: design records, risk analysis, process controls, measurement results and a signed Part Submission Warrant (PSW). Vehicle makers publish customer-specific requirements that add to or change the AIAG manual, so always read your customer's requirements alongside it.

PPAP is also used outside automotive, for example by industrial and off-highway equipment makers, often in a simplified form.

The five submission levels

Level	What is submitted to the customer
Level 1	Part Submission Warrant only (and, for designated appearance items, an appearance approval report)
Level 2	PSW with product samples and limited supporting data
Level 3	PSW with product samples and complete supporting data. This is the default level unless the customer says otherwise.
Level 4	PSW and other requirements as defined by the customer
Level 5	PSW with product samples and complete supporting data reviewed at the supplier's manufacturing location

The level decides what is submitted. The supplier is generally expected to complete and retain the applicable elements whatever the level.

The 18 elements, applied to a harness

Element	What it looks like for a wire harness
1. Design records	Harness drawing, wiring table, BOM, customer specifications
2. Authorized engineering change documents	Approved changes not yet on the drawing
3. Customer engineering approval	Where the customer requires it, for example validation results
4. Design FMEA	If the supplier is design responsible
5. Process flow diagram	Receiving, cutting, stripping, crimping, sealing, assembly, taping, test, inspection, packing
6. Process FMEA	Risks such as wrong terminal, low crimp, contact not locked, miswire
7. Control plan	How each risk is controlled: crimp monitoring, pull tests, electrical test, error-proofing
8. Measurement system analysis	Studies on crimp micrometers, pull testers, length measurement, electrical tester
9. Dimensional results	Lengths, branch positions and other drawing characteristics on the sample parts
10. Material and performance test results	Crimp performance to the customer's specification, material certifications, electrical results
11. Initial process studies	Capability studies on key characteristics, such as crimp height
12. Qualified laboratory documentation	Scope and accreditation of the labs used
13. Appearance approval report	Only for appearance items, which harnesses usually are not
14. Sample production parts	Parts from the production process
15. Master sample	A retained sample signed off by the customer
16. Checking aids	Formboards used as gauges, test fixtures, go/no-go checks
17. Customer-specific requirements	Records showing each applicable requirement is met
18. Part Submission Warrant	The signed summary declaration

Harness-specific points that trip up submissions

Crimp performance evidence. Customers often require crimps to be validated to a named specification, commonly SAE/USCAR-21 in North American automotive work, or to the vehicle maker's own standard. Plan the tests early; they take time.
Terminal and connector approvals. Many vehicle makers require the terminal and connector system itself to be validated, for example to SAE/USCAR-2. Confirm the parts on your drawing already have that validation.
Error-proofing in the control plan. Connector position assurance, terminal position assurance and electrical test coverage are expected to be shown, not assumed.
Measurement system studies for crimp height and pull force, not just for dimensions.
Run-at-rate. Some customers require a production trial at the planned rate before approval.

When a new PPAP is needed

A new or updated submission is generally required for a new part, a design change, a change of material or component source, a change of process or tooling, a move to a new location, or after production has been inactive for a period your customer defines. Customers also require notification before most changes. Check your customer's requirements for the full list and time limits.

PPAP and AS9102 FAI side by side

	PPAP	AS9102 FAI
Typical industry	Automotive	Aerospace and defense
Published by	AIAG, with vehicle maker requirements	SAE, for the IAQG
Main question	Can the process produce good parts consistently at rate?	Does the production process produce a part meeting every design requirement?
Risk analysis and control plan	Required elements	Not part of the report
Signed summary	Part Submission Warrant	Form 1

What to ask a supplier

Have you completed PPAP submissions for harnesses at Level 3, and for which kinds of customers?
Can you show a redacted control plan and process FMEA for a similar harness?
How do you perform crimp validation to the specification my customer requires?
Which measurement system studies do you already have for your crimp and test equipment?
How do you notify customers of changes?

Common questions

Is PPAP the same as first article inspection?

No. An AS9102 first article inspection verifies that a part meets its design requirements. PPAP includes dimensional and test results too, but also requires evidence that the process is understood, controlled and capable.

Can a supplier without IATF 16949 certification do PPAP?

Yes, PPAP is a process, not a certificate. Whether your customer accepts a supplier without IATF 16949 certification is a separate question for your customer's requirements.

Which PPAP level should I ask for?

Ask for the level your own customer requires. If you are the end customer, Level 3 is the default and provides complete evidence.