The Production Part Approval Process (PPAP) is the standardized procedure in the automotive industry for the approval of production parts before the start of serial production. Defined in the AIAG standard and anchored in IATF 16949, the PPAP proves that a supplier has fully understood the customer's design and quality requirements and is capable of reproducibly manufacturing components in the required quality and quantity.
A Digital PPAP replaces paper folders and email chains with a structured digital capture and management of all PPAP elements, providing direct access to production data, test results, and process parameters from the manufacturing system.
The 18 PPAP Elements: A Comprehensive Checklist
A complete PPAP consists of up to 18 elements that must be submitted or held for review, depending on the required submission level:
- Design Documentation: Drawings and specifications in the current revision.
- Engineering Change Documentation: Records of changes compared to predecessor versions.
- Customer Engineering Approval: Formal approval of the design.
- Design FMEA (DFMEA): Risk analysis of the design (if the supplier is design-responsible).
- Process Flow Diagram: Visualizing all steps from raw material to shipping.
- Process FMEA (PFMEA): Risk analysis of the manufacturing process.
- Control Plan: Documentation of how and when characteristics are inspected.
- Measurement System Analysis (MSA): Proof that gauges and test systems are accurate (Gage R&R).
- Dimensional Results: Full evaluation of all drawing dimensions on initial samples.
- Records of Material / Performance Tests: Certificates for hardness, tensile strength, etc.
- Initial Process Studies: Cpk and Ppk values for critical characteristics (Target: $C_{pk} \geq 1.67$).
- Qualified Laboratory Documentation: Proof of accreditation of the testing labs.
- Appearance Approval Report (AAR): For parts with aesthetic requirements.
- Sample Production Parts: Physical samples from the PPAP run.
- Master Sample: A signed sample retained at the supplier or customer.
- Checking Aids: Specific fixtures or gauges used for inspection.
- Customer Specific Requirements: Documentation of compliance with individual OEM rules.
- Part Submission Warrant (PSW): The summary cover sheet and formal supplier declaration.
The Five PPAP Submission Levels
The levels determine which elements must be physically submitted to the customer:
- Level 1: Only the PSW is submitted.
- Level 2: PSW with samples and limited supporting data.
- Level 3: PSW with samples and complete supporting data (Standard level).
- Level 4: PSW and other requirements as defined by the customer.
- Level 5: PSW with samples and complete data reviewed at the supplier's facility.
From Paper Chaos to Digital PPAP
Traditional PPAP folders can span hundreds of pages. Manual entry often leads to version conflicts, transcription errors, and "stale" data.
How Digital PPAP changes the process:
- Real-time Capability Data: Cpk values are pulled directly from the MES or SPC system, ensuring they reflect actual production rather than manually cherry-picked samples.
- Synchronized Documentation: Changes in the PFMEA automatically trigger updates or review requests in the Control Plan.
- Automated PSW Generation: The warrant becomes an automated summary of validated data instead of a high-pressure manual collection task.
- Direct Portal Integration: Structured data is uploaded directly to OEM portals (e.g., BMW iRoll, VW ForSQ), providing immediate status tracking.
The Role of MES in PPAP Efficiency
An MES (Manufacturing Execution System) provides the "proof of life" for a PPAP. It delivers validated production data, including machine parameters during the sample run, scrap rates, and full batch traceability. By pulling this data directly into the PPAP workflow, suppliers significantly reduce lead times and increase the credibility of their submissions.
FAQ
What happens if a PPAP is rejected?
A rejected PSW means no serial production may start. The supplier must correct the non-conformities (e.g., low Cpk values or dimensional deviations) and resubmit.
How long must PPAP documents be archived?
Typically, for the duration of the part’s production life plus at least one calendar year. However, many OEMs require 15+ years for safety-critical components.
What is the difference between PPAP and APQP?
APQP (Advanced Product Quality Planning) is the overall planning process. PPAP is the final output and evidence at the end of that process, proving all quality goals have been met.
When is a new PPAP required?
A resubmission is required for any significant change: new materials, sub-supplier changes, tool transfers, or manufacturing site relocations.