Before a new part arrives for the first time at the customer line, there is a process that determines whether it will be accepted. That process has two names that are often confused: APQP and PPAP.
APQP Is the Path. PPAP Is the Proof It Was Followed.
APQP —Advanced Product Quality Planning— is the planning methodology that orders the development of a new product from design to serial production. It defines phases, deliverables, and revisions. It is what the organization does.
PPAP —Production Part Approval Process— is the documentation package that the supplier delivers to the customer to demonstrate that its process can produce that part in a repeatable and consistent manner. It is what the organization tests.
What a PPAP Package Contains
The standard defines up to eighteen elements, and the customer decides which ones to require and at what level of presentation. The ones that almost always appear are:
The process flow diagram, which shows each operation from raw material receipt to shipment. The Process FMEA, which identifies the possible failure modes in each operation and the actions that control them. The control plan, which translates the FMEA into concrete instructions: what is measured, how often, with which instrument, and what is done when it goes out.
Then the evidence: dimensional results of the sample parts against the drawing, process capability studies on the critical characteristics, repeatability and reproducibility studies of the measurement systems, and material and performance test results.
And finally the part submission warrant, the document in which the supplier formally declares that all of the above is true.
Why a PPAP Is Rejected
A significant share of rejections are not technical. They are documentation issues.
The drawing revision predates the latest released one. The control plan does not cover a characteristic the customer flagged as critical. The repeatability study was done with an instrument whose calibration had expired. The sample parts do not come from a production lot but from a trial run, when the standard requires significant production. Or internal approval signatures are missing.
None of those things means the part is bad. They mean the file does not prove it is good, which, for the purposes of the process, is the same thing.
Where an External Quality Provider Comes In
At two different times.
During preparation, when the organization needs additional capacity to perform dimensional measurements, to lift the measurement systems studies, or to assemble the file without diverting the quality team from the current operation.
And after approval, when the customer imposes an early containment period —GP12— on the first production runs. That protocol requires additional inspection at 100% for weeks, and it is precisely the type of load that is advisable to contract rather than absorb.
Learn About the GP12 Service · Quality Consulting and Projects
