How to specify PPAP Submission on a drawing

PPAP Submission is the production part approval process used in the automotive supply chain, at four levels of evidence. It is used for proving that a production process can make the part repeatedly, before series supply starts. This entry explains what it is, what the numbers on a data sheet mean, and what to put on a drawing.

It is written from the point of view of the buyer and the drawing office: the values that are realistic in production, the ones that cost money, and the way the result is verified. Where an industry sets the requirement, food processing is used as the example: surfaces that clean down between production runs.

What belongs on the drawing

A clear drawing for PPAP Submission states the function, the tolerance and the verification, and leaves the route open where the function allows it.

• The feature and its tolerance: as the drawing, with capability on critical characteristics, applied to the features that locate the part.
• The material and its condition: any, with the certificate requirement.
• The surface finish: as specified on the drawing, called out only where it does something.
• The verification: IATF 16949 with a PPAP submission at the level stated by the customer, and the standard the report is written to.

Mistakes that cost money

• Submitting without a capability study on the critical characteristics, which makes the part more expensive without making it better.
• A control plan that describes a different process from the one that runs, which makes the part more expensive without making it better.

A workable note

Where a general note is used, say so once in the title block and keep the feature level call outs for the dimensions that matter. Identify the critical characteristics early, because they drive the study

Applications

PPAP Submission is used for proving that a production process can make the part repeatedly, before series supply starts, and in practice it appears most often in automotive series production, tier two supply, any customer working to IATF 16949, high volume repeat orders.

How it fits into a machining route

The route is fixed before the first part is cut, and it is the route rather than the individual setting that holds the result: the documentation effort and the capability study. Where a drawing calls for something the route cannot hold economically, that is raised at quotation rather than after the parts are made.

Standards, documentation and what is issued

The documentation requirement is IATF 16949 with a PPAP submission at the level stated by the customer. Material is supplied against a certificate where the application calls for it, inspection results are recorded with the job, and the records are kept so that a repeat order can be compared with the first instead of being measured from scratch.

A full dimensional report plus a capability study is the verification step. Where a customer format or a standard report is required, it is agreed before the batch starts, because a report written after the event is a report nobody can use.

Frequently asked questions

What tolerance should be specified for PPAP Submission?

as the drawing, with capability on critical characteristics is realistic in production. Tightening it beyond the functional requirement increases cost without improving the part.

Which material is usually used?

any is the usual choice, supplied against IATF 16949 with a PPAP submission at the level stated by the customer.

How is the result verified?

A full dimensional report plus a capability study, with the results recorded so a repeat order can be compared with the first.

What is the most common mistake?

A control plan that describes a different process from the one that runs.

How long does it take and what does it cost?

A realistic cycle is a day of documentation for a level 3, and the cost driver is the documentation effort and the capability study.

Related capability

If you are specifying PPAP Submission on a drawing and want a second opinion on the route, send the model and the quantity. The first response is a manufacturability review with the likely risk points and a quotation, so the decision can be made on facts rather than on a price alone.

Machining, inspection and documentation are handled in one place, which is why the dimensional report and the material certificate arrive with the parts rather than after them.

Related entries

These entries sit next to PPAP Submission in the encyclopedia: EN 10204 Material Certificates, Geometric Dimensioning and Tolerancing, CNC Milling. Reading them together gives a fuller picture of how the process, the material and the measurement affect each other.