PPAP and part, process and service qualification plan

What a qualification plan is

Before a new part, process or service goes into production, the customer and the supplier agree a qualification plan: the evidence the supplier will produce, who owns each item, and when it is due. For manufactured parts the plan usually follows the production part approval process (PPAP), published by AIAG for the automotive industry and widely copied elsewhere. The purpose is stated in the CSQP Body of Knowledge: to show that the supplier understands the requirements and that its process can make parts with consistent quality during an actual production run at production rates.

The 18 PPAP elements

Design records; engineering change documents; customer engineering approval; design FMEA; process flow diagram; process FMEA; control plan; measurement system analysis; dimensional results; material and performance test results; initial process studies; qualified laboratory documentation; appearance approval report; sample production parts; master sample; checking aids; customer-specific requirements; and the part submission warrant (PSW). The PSW is the one-page summary the supplier signs to declare that everything else is done and conforms.

Submission levels

• Level 1: the warrant only (plus the appearance approval report for appearance items).
• Level 2: the warrant with product samples and limited supporting data.
• Level 3: the warrant with samples and complete supporting data. This is the default unless the customer says otherwise.
• Level 4: the warrant and whatever else the customer defines.
• Level 5: the warrant with samples and complete data, reviewed at the supplier's site.

The "At level" column shows the code from the PPAP table: S, submit and keep a copy; R, keep on file and show on request; *, keep, and submit if asked. Whatever the level, the supplier must have every applicable element done and on file. The level changes what is sent, not what is done.

The acceptance criteria the tool checks

• Initial process studies: Ppk above 1.67 meets the criteria; 1.33 to 1.67 may be acceptable with the customer's agreement; below 1.33 does not, and needs a corrective action plan and containment such as 100% inspection. Use at least 100 readings, for example 25 subgroups of 4.
• Gauge R&R: under 10% acceptable; 10% to 30% may be acceptable depending on the application; over 30% not acceptable.
• Run at rate: good parts per hour in the significant production run (by default one to eight hours and at least 300 consecutive parts) compared with demand per day ÷ planned hours per day.

Beyond parts

A process or a service (calibration, laboratory testing, software, design) is qualified the same way in principle: a provider audit, the requirements and critical-to-quality characteristics agreed with the supplier, an inspection or verification plan, validation (IQ, OQ, PQ for equipment and processes), and evidence such as a certificate of conformance (CoC) or certificate of analysis (CoA). A production readiness review then confirms the plan was executed. The first article inspection and control plan tools produce two of the elements.

On the exam

The CSQP covers developing the qualification plan, with its audit, calibration, sample size, first article, MSA, PFD, FMEA, control plan, CTQ, capability, material and performance testing, appearance approval and validation items (III.C.3), PPAP requirements and production at rate (III.C.4), and interpreting the results, including CoC, CoA and production readiness reviews (III.C.5). The CQPA describes first-article and other approval methods (IV.C), and the CQE covers supplier qualification (I.H.1), IQ/OQ/PQ (III.D) and control plans (IV.A). Expect to name the elements, choose a submission level, and judge a Ppk or %GRR against the criteria.

Other tools and templates