Review a Supplier Change Notice After Part Approval
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A part approval is a controlled baseline, not a permanent assumption that every later shipment is made the same way. A supplier may change material, tooling, heat treatment, manufacturing location, a subcontractor or even inspection software while the drawing number stays unchanged. If the buyer reviews only the drawing revision, the changed production route can pass through purchasing and receiving without a clear decision.
A supplier change notice should therefore answer four separate questions: what differs from the approved state, what evidence supports the change, which production lot first contains it, and who is authorised to accept it. This guide provides a practical review method for buyers and quality teams. It does not grant approval, define a universal PPAP level or replace order-specific requirements. For the earlier sourcing decision, keep the broader undercarriage supplier-selection context in its own record.
Recognise what has changed since approval
Begin with the approved baseline. Record the part number, drawing and revision, specification set, approval reference, supplier legal entity, production site, process route, key material designation, controlled subcontractors and any tool or program identifiers that formed the original decision. A notice that describes only the proposed future state cannot show what actually changed.
Then write a before-and-after statement in operational terms. “Process improvement” is a reason, not a description. A useful statement might say that heat treatment moves from subcontractor A at one site to subcontractor B at another site, while the drawing, nominal chemistry and final hardness requirement remain unchanged. That wording exposes the changed mechanism even though the customer-facing part revision has not moved.
Change categories are prompts for investigation rather than automatic risk scores. In its supplier request-for-change process, Graco gives company-specific examples involving product, process, material, tool, subcontractor and location changes. Infineon and Littelfuse publish their own notification and approval expectations. These sources show why buyers ask about more than drawings, but their forms and thresholds belong to those companies. Apply the customer contract and the agreed supplier controls for the actual order.
At minimum, the notice record should identify the affected part and approval, the supplier owner, the reason, whether the proposal is temporary or permanent, the planned implementation date and every affected site, source, tool or process. Ask whether work in progress, finished stock or material already ordered was made under the old state. A calendar date without inventory status does not define a clean boundary.
Do not combine notification with approval. “Supplier notified buyer” means the proposal reached the review path. “Evidence received” means the package can be assessed. “Approved” requires the person or function named by the applicable agreement to issue a controlled decision. A supplier’s internal approval, a buyer’s acknowledgement email and an authorised customer release can be three different events.
Also test scope. A change accepted for one part, site or process does not automatically transfer to a similar part. If a common heat-treatment line serves several undercarriage components, list each affected part and approval explicitly. Leave unlisted items outside the decision until their scope is confirmed.
Ask for the change evidence package
Scale the evidence to the function that could be affected and to the mechanism of change. A label layout correction and a new steel grade do not need the same review. The first may require document and traceability checks. The second may require material qualification, dimensional results, mechanical testing, process evidence and a comparison with the approved state. Avoid assigning a submission level merely because a familiar industry form uses one.
Request a controlled before-and-after description, the supplier’s risk assessment, and the documents that show how the process will be managed. Depending on the change, those documents can include a drawing, process flow, control plan, work instruction, material certificate basis, tooling record, special-process qualification, inspection plan or software validation. Each submitted file should identify its revision and the part, site and process to which it applies.
Validation results need traceable samples. Record the sample or lot identity, manufacture date, material heat where relevant, process route and the measurement or test method. A spreadsheet of acceptable numbers is weak evidence if the reviewer cannot connect it to the changed process. Where the supplier compares old and new production, confirm that the samples are reasonably comparable and that the claimed difference is evaluated against the order requirement.
The Infineon supplier product-change page is an example of a structured notice process that links change information, affected products, implementation timing and qualification evidence. Its electronics context does not set rules for undercarriage parts. The useful general lesson is to keep the proposed change, evidence and affected-product scope connected in one review trail.
The Littelfuse supplier PPAP manual provides another company-specific example of notification for changes to previously approved product or process. Use it to understand the type of linkage a customer may request, not to infer that its PPAP level, timing or retention rules apply to a different buyer.
Check for open deviations and unresolved findings. A validation lot made under a temporary concession may not demonstrate the normal future process. Record any conditions, exclusions and test limitations instead of reducing the package to “pass.” If evidence is incomplete, identify exactly what is missing and keep the decision open.
Ask how the supplier will implement the change and how it would contain or reverse it if verification fails. The answer should cover updated documents, operator or subcontractor readiness, old material disposition, traceability and reaction to an adverse result. A technically promising change can still be poorly controlled at the transition.
Control the first affected production lot
The implementation boundary converts an approved proposal into controlled production. Record the first changed manufacture date and the first affected lot, batch or serial identifier. If the process does not use serial numbers, identify the traceability unit that receiving and the supplier can both find later. The identifier should appear consistently in the notice, production record, shipment documentation and any agreed first-lot evidence.
Separate four populations: finished stock made under the old approval, old-state work in progress, the first changed production, and later changed production. State whether each can be completed, shipped, held, reworked or scrapped. Mixing old and new stock under one undifferentiated lot makes it impossible to reconstruct which baseline produced a field or inspection result.
Use a shipment block when approval or the effective boundary is unresolved. A proposed implementation date is not permission to manufacture or ship. The release authority must come from the contract, quality agreement, purchase order or other controlled customer requirement. This article cannot identify that authority for a particular transaction.
If the order requires a pilot run, first article or enhanced inspection, connect it to the first affected lot. Define what will be checked, the acceptance basis, who reviews the result and whether shipment remains blocked during review. “First article complete” is insufficient when the record does not show which configuration was tested.
An unknown first affected lot affects both sides of the boundary. The buyer cannot know whether stock labelled as old is truly old, and the supplier cannot prove which shipment began the new state. Resolve the traceability gap before treating either population as controlled. When work in progress crosses the proposed date, use actual process and lot records instead of the date alone.
Record which open purchase orders and scheduled shipments are affected. A valid technical decision can still be applied to the wrong commercial scope. If one customer order permits the change and another does not, the supplier needs segregation and order-level release instructions. Do not silently convert approval for one order into a standing approval.
Prepare containment and rollback actions before the first changed shipment. These can include holding identified lots, restoring the prior process where feasible, increasing verification, notifying affected parties and preserving suspect samples. The exact response depends on the risk and agreement, but ownership and traceability should be clear before implementation.
Keep the old and new approval records connected
Preserve the original approval as historical evidence. Do not overwrite it with the new result. The change record should point back to the old approval and forward to the authorised decision, its conditions, the effective lot or date and the documents that support it. This chain allows a later reviewer to determine which baseline governed a particular shipment.
Keep the notice version, evidence index, review comments and final disposition together. If the supplier revises the proposal during review, show what changed between notice versions. An approval of version one should not be assumed to cover a broader version two. Supersede obsolete documents in the controlled system while retaining their history.
Write the decision precisely: approved, approved with conditions, rejected or more evidence required. Identify the authorised decision owner and date. For conditional approval, record the condition, responsible party, due point and consequence if it is not met. Avoid ambiguous dispositions such as “noted” or “looks acceptable.”
Close the record only after the agreed post-change verification is complete. That verification might confirm the first affected lot, review its inspection or test results, check document implementation and reconcile shipped orders. Define what would trigger revalidation, such as another site, tool, material source or process change. Approval remains limited to the recorded scope.
| Case | Baseline and proposed change | Evidence and decision | Effective boundary | Required action |
|---|---|---|---|---|
| Normal | Old approval and before/after process, site and source are identified for the listed part | Risk-based evidence is traceable; authorised approval and conditions are recorded | First changed manufacture date and lot align with stock, WIP and shipment records | Release the recorded scope under the stated conditions and complete post-change verification |
| Missing | Notice says “new heat-treatment supplier” but omits the old source or affected parts | Qualification summary has no sample or lot identity | Proposed date is supplied, but the first affected lot and WIP status are unknown | Keep approval and shipment open; request the missing scope, evidence and boundary |
| Conflict | Notice identifies one site, while submitted reports identify another | Buyer record is pending, but supplier status says implemented | A shipment lot predates the stated change yet carries the new process code | Block affected material, reconcile the records and obtain an authorised disposition |
The record should also list affected orders, related deviations, superseded files and the closure owner. Unknown fields stay open; they are not evidence that the old or new state applies. If the supplier and buyer records disagree, preserve both versions and resolve the conflict through the authorised route rather than editing history to match the expected answer.
A good supplier change review produces a traceable boundary, not merely a signed form. The buyer can see the approved past state, the proposed future state, the evidence used to assess it, the authority that decided it and the first lot governed by the decision. Until those elements agree, the change remains unresolved for production and shipment.