Part Submission Warrant (PSW)

The Part Submission Warrant (PSW) is the concluding approval document in the PPAP process (Production Part Approval Process), confirming that a supplier has fulfilled all required evidence and is capable of manufacturing the part to series quality at series volume. It is not a self-declaration of quality by the supplier – it is a formal commitment to the customer that all PPAP elements have been completed in full, in compliance with the applicable standard, and under actual production conditions.

What the PSW Is – and What It Is Not

A widespread misconception in the supply chain: the PSW is treated as an administrative closing document filled out once everything else is done. That framing is incorrect – and it is the most common root cause of invalid or rejected PSW submissions.

The PSW is a legally binding declaration. By signing it, the supplier formally confirms that the submitted sample parts were manufactured under production conditions – meaning production tooling, production process, production material, and production run rate. If that is not the case and the PSW is signed regardless, this is not merely a quality issue – it is a liability issue.

The PSW also does not replace the individual PPAP elements. It is the summary and confirmation that all required elements are present – not a substitute for them.

PPAP Levels and the PSW: What Must Be Submitted

The scope of the PPAP submission – and therefore the documents the PSW confirms – depends on the agreed PPAP level. The AIAG PPAP standard (4th Edition) defines five levels:

Level 3 is the default in the automotive industry. Level 1 appears simple – but all PPAP elements must still exist at the supplier and be available for review on demand. The difference is in submission scope only, not in documentation obligation.

The 18 PPAP Elements the PSW Confirms

By signing the PSW, the supplier declares that all applicable elements of the following list are complete and compliant:

Not every element is mandatory for every part – the required scope depends on part complexity, customer requirements, and PPAP level. Safety-relevant characteristics (Special Characteristics) consistently increase the required evidence scope.

What the PSW Contains – and What Is Frequently Filled Out Incorrectly

The AIAG-standard PSW form includes the following key fields:

Part number and revision level: Must match the approved drawing exactly. Discrepancies – including minor revision errors – result in immediate rejection.

Part weight: Must be measured on a production part, not a prototype or CAD model. Deviations from the drawing weight exceeding 5% typically trigger customer queries.

Reason for submission: New part, design change, process change, supplier change, or tooling change – the correct submission reason must be stated accurately. An incorrect reason renders the PSW formally invalid.

Production quantity and production location: The stated location must correspond exactly to the facility where series production takes place. A PSW issued for Plant A does not automatically apply to Plant B – even if the same supplier operates both.

Signature and title: The PSW must be signed by an authorized individual with quality responsibility. A signature without a stated title, or from an unauthorized person, is formally invalid.

Practice Warning: When an Approved PSW Loses Its Validity

An approved PSW is not a permanent release. It loses validity automatically and requires resubmission upon the following events:

Change to part design or drawing. Change of raw material or sub-supplier for safety-relevant components. Relocation of production to a different facility or manufacturing line. Resumption of production after an interruption exceeding one year (customer-dependent, commonly 12 months). Process changes affecting Special Characteristics.

This point is consistently underestimated in practice. A supplier changes the sub-supplier for a raw material, does not notify the OEM, and continues production under the existing PSW. When the OEM discovers this during a supplier audit, it constitutes a Major Finding – the active production approval status can be withdrawn.

Practical Example: PSW Submission for a Structural Component

A Tier-2 supplier manufactures stamped parts for a seat frame. First submission under PPAP Level 3.

The quality team has assembled all 18 elements. During the final review before submission, it becomes apparent that Cpk values for two Special Characteristics are 1.52 and 1.48 – the customer minimum standard requires 1.67.

Option A – submit PSW regardless: The customer will identify the values in the PPAP package and reject the PSW. Additionally, it creates the impression that the supplier is unaware of or disregarding the requirements.

Option B – submit PSW with Deviation Request: The supplier documents the deviation transparently, presents a corrective action plan with a target date, and requests a time-limited interim approval. This is the normatively correct approach – it demonstrates process competence, not weakness.

Option C – stabilize the process before submission: Identify and resolve the root cause of the variation, run a new measurement, then submit. Takes longer, but results in a clean approval with no open items.

Which option is chosen depends on schedule pressure and process maturity. Option A is not an option.

FAQ: Part Submission Warrant in Practice

1. Who is authorized to sign a PSW? A person with quality responsibility and corresponding signing authority within the organization – typically the Quality Manager or an explicitly delegated individual. Many OEMs additionally require name, title, phone number, and email address for follow-up contact.

2. What happens if a PSW is rejected? The supplier may not ship production parts until an approved PSW is in place. Deliveries made on the basis of a rejected PSW are considered unapproved parts – with corresponding liability exposure and risk of delivery stop. In urgent situations, the customer may issue a time-limited Interim Approval, which carries mandatory corrective action obligations with a defined completion date.

3. Does the PSW need to be renewed for unchanged series production? No – as long as none of the change events listed above occur. An approved PSW remains valid until a resubmission trigger arises. However, many OEMs conduct regular supplier audits that include verification of PPAP documentation currency and completeness.

4. Does a PSW apply to spare parts deliveries? Not automatically. Spare parts business frequently operates under separate approval processes that differ from the series PPAP. If spare parts are manufactured using different tooling or from a different production facility than the series parts, a separate submission is typically required.

5. What does "Interim Approval" on a PSW mean? An Interim Approval is a time- and volume-limited special release issued by the customer when a supplier has not yet fully met PPAP requirements but delivery timelines require parts to be used in the interim. It binds the supplier to close all open items by a defined date. An Interim Approval is not a normal operating state – it is an exception with consequences if the agreed deadline is not met.

Strategic Value

The PSW is the final control point before production launch – and simultaneously the moment at which all upstream quality processes are verified for completeness. Organizations that run PPAP and PSW as a structured process rather than a formality have a measurable advantage: shorter customer approval cycles, fewer queries, fewer resubmissions, and a stable foundation for series launch. The PSW is not the end of the quality process – it is the proof that the quality process worked.