PPAP Approved and Archived? —— Five Steps to Maintain and Resubmit PPAP Post-Production

1. A PPAP Approved for Three Years, Revealing Eleven Issues During Customer Audit

A Tier 1 automotive interior functional parts company supplies door panel clip assemblies. In late 2022, the PPAP was approved, and the Part Submission Warrant (PSW) was signed off smoothly. The project team celebrated and archived the documents, and no one touched the green folder for the next three years.

In 2025, during the customer's annual process audit, the auditor compared the on-site conditions with the PPAP-approved baseline, becoming increasingly concerned: the material for the injection-molded parts had been quietly changed from the approved PC/ABS grade to the same grade from another supplier, citing an 8% cost reduction, but no new material reports were generated, nor was the customer notified; two sets of molds were moved from the old plant to the new plant, with only trial molding conducted, not full-size inspection; the clamping force parameter of the injection molding machine in the control plan had been adjusted twice by the on-site process engineer, but the document was not updated. The auditor was even more surprised upon reviewing the records—within 14 months after approval, the company had made 11 changes related to the PPAP baseline, and only 3 of these changes were proactively communicated to the customer.

The conclusion was a major nonconformity issued by the customer: the PPAP status was deemed invalid, and the company was required to resubmit PPAP for all part numbers involved in the changes and trace 26 batches of shipped products. The customer's quality engineer put it bluntly: "We didn't approve the samples you submitted three years ago; we approved your 'qualification' to consistently produce according to that state. You've lost that qualification."

This is not an isolated case. Many companies view PPAP as a "one-time exam before production"—once passed, it is archived, and subsequent changes, relocations, material swaps, and process modifications are left unmanaged. It is only when a customer audit or complaint arises that they realize the PSW has become a mere formality.

2. Why PPAP is Not a "One-Time Deal"

Let's revisit the essence of PPAP. The Production Part Approval Process (PPAP) does not confirm the quality of a single sample but rather verifies whether "the organization has understood all the requirements of the customer's engineering design records and specifications and has the capacity and capability to consistently meet these requirements in the production process designed according to these specifications." The signature on the PSW is essentially a continuous commitment by the organization to maintain "production status consistent with the approved baseline," not an endorsement of a specific batch of samples.

The AIAG PPAP manual clearly states that production part approval remains valid until the customer formally revokes it in writing, but the organization must be responsible for any subsequent changes that affect the approved status—once the process, materials, location, or tooling deviates from the approved baseline, the organization is obligated to reassess and resubmit to the customer. Similarly, the "Product Approval Process" clause in IATF 16949 requires that the organization revalidate products at the frequency requested by the customer and notify the customer and obtain approval for any changes that impact the product.

Understanding this, it becomes clear that maintaining PPAP post-production is as important as submitting it pre-production: submitting proves "I can do it," while maintaining proves "I always do it." Many companies invest heavily in APQP and strive to pass PPAP, but they casually discard this commitment after production starts—ten months of trust built can be erased by a single unauthorized change.

3. Five-Step Method to Maintain and Resubmit PPAP Post-Production

Step One: Establish a "PPAP Baseline Archive" to ensure traceability of the approved status. For each approved part, create a baseline card with precise fields: part number and name, approved version and date, PSW signatory, submission level, production site and line, key material grade and supplier, mold and tooling numbers, process capability requirements, control plan version, and customer contact. This card serves as the "reference point" for all post-production changes—without a baseline, it is impossible to clarify what has been changed. The archive is maintained by the quality engineer, updated synchronously with PPAP resubmissions, and included in the annual internal audit scope.

Step Two: Integrate a "Change Trigger Matrix" into the engineering change process. The core mechanism for maintaining PPAP is to embed a trigger matrix in the change management process, clearly defining which changes must be notified to the customer, which require resubmission, and at what level. Typical changes that trigger resubmission include: modifications to design records or specifications, changes in material or supplier, relocation of production sites, changes in process methods (including forming parameters, cycle times, and processing methods), major repairs or replacements of portable tooling and molds, substantial changes in inspection methods or gauges, and significant increases in production cycle times. Each item in the matrix should specify the responsible person and timeline—changes are assessed by the initiating department, reviewed by the quality department, and, if necessary, a customer notification is issued within a week. Without a matrix, the change process is like an intersection without traffic lights, and each change is a gamble.

Step Three: Ask "Do we need to resubmit?" before implementing any change. After any change is verified through trial production and before formal implementation, the project or process engineer should fill out the "Change and PPAP Impact Assessment Form": what is the change content, which approved documents (drawings, DFMEA/PFMEA, control plan, material reports, process capability) are affected, what category does it fall under according to the matrix, does it require customer approval or just notification, and what is the suggested submission level. For changes requiring customer approval, obtain written consent before switching, even if it means waiting two weeks; for those requiring only notification, document and file according to the customer's required format. This step is crucial for transforming "post-facto remediation" into "pre-emptive control."

Step Four: Conduct annual revalidation to keep the PPAP package "fresh." Most Tier 1 suppliers and OEMs require suppliers to conduct annual revalidation, covering full-size inspection, material and performance testing, and process capability revalidation. A common practice is to select a production batch each year and retest according to the approved PPAP elements, comparing the results with the baseline data and archiving the annual revalidation report. Even without explicit customer requirements, the organization should proactively conduct annual self-revalidation for high-risk parts (safety parts, special characteristics parts, parts with historical customer complaints)—the value of revalidation is not just to satisfy the customer but to systematically confirm each year whether the "capabilities committed at the time of approval" still exist.

Step Five: Dynamically maintain the PSW ledger to make the approved status "visible." Establish a company-wide PPAP status ledger, with each part listed on a separate line: current status (approved, temporary approval, invalid, pending resubmission), baseline version, date of the last revalidation, ongoing changes, and progress of resubmissions. At monthly quality meetings, list parts with "pending revalidation" or "unresolved changes" as tracking items, managed with red, yellow, and green indicators. This ledger also serves as a "repository" for customer audits—when the auditor asks, "Has this part been changed?" being able to produce complete records within five minutes is far more professional than spending three hours flipping through file folders.

4. Five Common Pitfalls

Pitfall One: Implementing changes without notifying the customer. This is the most fatal mistake. Some companies believe that "the change is minor, and the customer won't notice," or they fear that notification will trigger an audit and delay delivery. However, the nature of changes discovered during a customer audit versus those proactively reported is entirely different: the former is a breach of trust, leading to re-submission of PPAP at best and revocation of approval and supply suspension at worst. The cost of sending a formal notification before a change is far less than the cost of being traced and isolated.

Pitfall Two: Focusing only on signing the PSW, neglecting to update supporting documents. Some companies, upon receiving a customer's "resubmission" request, only sign a new PSW page and do not update material reports, full-size data, or process capability studies—when the submission level is higher than 2, this is equivalent to submitting an empty document. The PSW is just the cover; the data supporting it is what the customer truly needs to see.

Pitfall Three: Conducting annual revalidation as a formality, with data "filled in" rather than measured. Revalidation reports may directly copy old dimension data, use historical material reports, and not re-calculate process capability. Such revalidation can fool document reviews but not on-site sampling during customer annual audits. If the sampled data does not match, the situation is worse than not revalidating at all.

Pitfall Four: Ignoring changes in sub-suppliers. Many companies focus only on their own operations: changes in material sub-suppliers, such as switching suppliers, altering formulas, or relocating, go unnoticed until the customer traces the material reports and finds discrepancies. Maintaining PPAP must extend to sub-suppliers—changes in the source of key materials should be included in the trigger matrix just like changes in the company's own factory.

Pitfall Five: Failing to revalidate process capability after major mold repairs or production line speed increases. Changes like major mold repairs, equipment relocation, and cycle time increases, which do not alter the product design but significantly impact process capability, are often overlooked. The Cpk commitment in the original PPAP is based on old molds and old cycle times; when conditions change, the capability commitment becomes invalid, and initial process capability studies must be redone and records updated.

5. In a Nutshell

PPAP is not a graduation certificate before production but a "continuous qualification" during production—establish the baseline, manage changes, and conduct revalidations to ensure the approved status does not silently become invalid.

The approval of PPAP is the starting point; maintaining it is the commitment.

Knowledge code: 8.3.3

Version: v20260904

Author: QTank QTank is dedicated to providing systematic professional knowledge, methodologies, and practical tools for quality management practitioners, helping companies continuously improve their quality capabilities.