For many suppliers, the word PPAP brings back memories of late nights assembling binders before a customer deadline. It doesn't have to be that way. PPAP is simply the evidence that your process can make the part right, consistently, at the agreed rate. If you plan it from the first day of a project, most of the evidence builds up naturally.
This guide gives a practical overview. Always follow your customer's specific requirements, which take precedence over any general description.
What PPAP proves
PPAP answers the customer's questions before mass production starts:
- Do you understand all our requirements?
- Have you analysed the risks in your process?
- Can you measure the important characteristics reliably?
- Is your process capable of meeting the tolerances?
- Can you produce at the quoted rate, with production tooling, people and conditions?
Typical PPAP elements
Customers commonly ask for some or all of these, depending on the part and submission level:
- Design records — the drawing and specifications at the correct revision.
- Engineering change documents, if any.
- Customer engineering approval, where required.
- Design FMEA, if the supplier is design-responsible.
- Process flow diagram.
- Process FMEA.
- Control plan.
- Measurement system analysis studies.
- Dimensional results — every dimension and note on the drawing, measured on sample parts.
- Material and performance test results.
- Initial process studies — capability for special characteristics.
- Qualified laboratory documentation.
- Appearance approval, for appearance items.
- Sample production parts.
- Master sample.
- Checking aids.
- Customer-specific requirements records.
- Part submission warrant — the summary declaration signed by the supplier.
Many of these are covered in our guides to PFMEA, control plans, gauge R&R and first article inspection.
Submission levels
The customer specifies how much is submitted. In the commonly used scheme, level 1 is the warrant only, level 3 — often the default — is the warrant with product samples and complete supporting data, and level 5 means everything is reviewed at the supplier's site. Even when little is submitted, the supplier is usually expected to have every element ready and retained.
Plan PPAP from the quote
The biggest PPAP problems start at quotation: a tolerance nobody can hold, a test requiring equipment the supplier doesn't own, a material that isn't available, or a timeline that ignores tool lead time. At quote and kick-off:
- Review the drawing and specifications line by line, and raise questions early.
- Identify special characteristics and the capability they will need.
- List the tests and who will do them — in-house or an external lab.
- Agree the submission level and due date.
- Build a project plan with tooling, gauges, trial run and each PPAP element.
The production trial run
PPAP parts must come from a significant production run using production tooling, gauges, materials, operators, cycle time and environment — not from the toolroom with the best operator on a good day. The customer usually specifies the quantity. Use the run to:
- Collect samples for full dimensional layout.
- Collect data for capability studies on special characteristics.
- Confirm the cycle time and the quoted rate.
- Test the control plan, work instructions and check sheets in real conditions.
- Record problems and fix them before submission.
Dimensional results
Number every dimension, note and specification on a ballooned drawing and record the measured value for each on the required number of samples, with the gauge used. "OK" is not a result — record actual values. Any out-of-tolerance dimension must be resolved before submission, or a deviation must be agreed with the customer in writing.
Capability studies
For special characteristics, initial process studies show whether the process is capable. Customers specify the index and threshold they expect. If capability is short, typical responses are to improve the process, increase inspection temporarily with the customer's agreement, or both.
Managing changes after approval
Approval applies to the process as submitted. Changing material source, subcontractor, tooling, process method, location or the design itself may require customer notification and a new or updated PPAP. Build a simple change control step into your engineering change process: before any change, ask whether the customer must be notified. Unauthorised changes are one of the fastest ways to damage a customer relationship.
Keeping PPAP records organised
Each part number should have a complete, current PPAP package that can be found in minutes: revision of every document, approval status, submission date and customer approval. Annual layout or requalification requirements, where customers specify them, should be scheduled like any other recurring task.
An example: a new bracket programme
A sheet metal supplier won five new brackets for a commercial vehicle customer. Instead of preparing PPAP at the end, the project lead created a checklist for each part at kick-off, with an owner and due date for every element. The PFMEA and control plan were drafted during tool build, gauges ordered early so MSA could be done before the trial, and coating tests booked with an external lab in advance. All five PPAPs were submitted on time and approved first time — the first time the company had managed it.
Common mistakes
- Starting PPAP preparation after the trial run.
- Trial parts made with prototype tooling or special attention.
- Dimensional results recorded as "OK" instead of values.
- Documents at different revisions to the drawing.
- Changes made after approval without notifying the customer.
How software helps
Quality and document software can hold PPAP checklists per part, link elements to the correct drawing revision, store measurement and capability data, and track approval status and requalification dates. Engineering change workflows can prompt customer notification before changes go live. See quality management software and engineering change management.
Talk to us about organising quality planning and PPAP records.
Frequently asked questions
What does PPAP stand for?
Production Part Approval Process — a set of evidence a supplier provides to show that its production process can consistently make parts that meet all customer requirements at the quoted rate.
Is PPAP only for automotive?
It originated in automotive, but aerospace, heavy equipment, electrical and industrial customers use PPAP or similar first-production approval processes.
What are PPAP submission levels?
Levels define how much evidence is submitted to the customer versus retained at the supplier. A common scheme runs from level 1 (warrant only) to level 5 (everything reviewed at the supplier's site). The customer specifies the level.
When is a new PPAP needed?
Typically for new parts, engineering changes, new or moved tooling, new subcontractors or material sources, process changes and after long production gaps. Check your customer's requirements and notify them before making changes.
How long does PPAP preparation take?
It depends on the part and the number of elements required, but planning it from the start of the project avoids last-minute rushes.
