Ensuring Compliance with AS9100: A Guide to Auditing Material Test Reports | My ISO Consultants
Updated: Sep 18
Material Test Reports (MTRs) can provide important evidence that externally provided materials meet specified requirements, but receiving the report is not enough by itself when the report is being used to verify product conformity. Under AS9100, an organization that uses external-provider test reports to verify products needs a process for evaluating the report data to confirm that the product meets applicable requirements. When raw material has been identified as a significant operational risk, the organization must also have a process for validating the accuracy of those test reports.
For internal auditors and quality teams, the key is to determine whether the organization's MTR process is actually capable of supporting reliable product acceptance, traceability, and risk control rather than simply checking that a document is present.
2026 AS9100 Standards Note
As of September 2026, 9100:2016 remains the current published aerospace quality management standard. IAQG is developing the next IA9100 revision, but organizations should continue auditing and maintaining their quality management systems against the current published requirements until the new standard and formal transition guidance are released.
What Does AS9100 Require for Material Test Reports?
The material test report requirements are addressed within Clause 8.4.2, which covers the type and extent of control applied to externally provided processes, products, and services. IAQG guidance highlights two related but different activities: evaluating test report data and, in higher-risk situations, validating the accuracy of the report.
Evaluation of Test Report Data
If an organization uses an external provider's test report as part of product verification, it needs a process to evaluate the data in the report and confirm that the product meets the applicable requirements. The review should therefore go beyond confirming that an MTR was received or that the material description matches a purchase order.
Depending on the material and the requirements, the evaluation may include comparing reported chemical composition, mechanical properties, performance values, material characteristics, or other specified results against the applicable acceptance criteria.
Validation of Test Report Accuracy for Significant-Risk Raw Material
AS9100 adds another level of control when the customer or organization has identified raw material as a significant operational risk. In those situations, the organization needs a process to validate the accuracy of the test report. IAQG clarification material states that this validation can be performed internally or by an external source, and that the organization determines the appropriate method and frequency based on its risks and requirements.
Validation could include appropriate sample testing, laboratory analysis, functional or performance testing, destructive testing, or another technically suitable method. The specific approach should match the material, product requirements, customer requirements, and level of operational risk.
Evaluation and Validation Are Not the Same Thing
This distinction is important during an audit. Evaluation asks whether the data shown on the MTR demonstrates conformity to the applicable requirements. Validation addresses whether the reported test data itself is accurate when the raw material presents a significant operational risk.
Not every raw material automatically requires independent retesting. The organization should be able to explain which raw materials or conditions trigger additional validation and why its chosen validation method and frequency are appropriate.
How to Audit an AS9100 Material Test Report Process
A useful audit should follow the material from the purchasing and receiving requirements through the MTR review and product-acceptance decision. Rather than reviewing reports in isolation, verify that the process connects the right material, specification, test results, supplier information, and acceptance criteria.
Select a risk-based sample of received materials for which external-provider test reports are used as evidence of conformity.
Verify that the material, heat, lot, batch, or other applicable identification is traceable to the corresponding MTR and received product.
Confirm that the organization identified the applicable material or product requirements and is using the correct acceptance criteria.
Check whether the relevant MTR data was actually evaluated against those requirements before the material was accepted for use.
Review who is authorized and competent to perform the evaluation and how completion of the review is documented.
For raw materials identified as a significant operational risk, verify that the required accuracy-validation process was performed using the organization's defined method and frequency.
Review what happens when MTR data is missing, inconsistent, outside requirements, or cannot be validated.
Verify that supplier controls, customer requirements, and any applicable purchasing flow-down requirements support the organization's MTR process.
Does AS9100 Require Every MTR to Be Independently Retested?
No fixed universal retest frequency such as one out of every 10 or 20 reports is prescribed by AS9100. If external-provider test reports are used to verify products, the organization must have a process that evaluates the data and confirms that applicable requirements are met. For significant-risk raw material, the organization must also define an appropriate process for validating test report accuracy.
The frequency and method of that additional validation should be determined by the organization based on factors such as operational risk, customer requirements, material criticality, supplier performance, previous validation results, and other relevant controls. An auditor should evaluate whether the defined process is appropriate and whether the organization is following it consistently.
Can a Supplier or Outside Laboratory Perform Part of the Verification?
An organization may use qualified external sources to support testing or validation, but outsourcing an activity does not remove the organization's responsibility for controlling externally provided products and ensuring that applicable requirements are met. The organization should define what the external provider is expected to do, retain appropriate evidence, and maintain enough oversight to support its product-acceptance decision.
Common Material Test Report Audit Problems
The MTR is filed but no one verifies the reported results against applicable requirements.
The material is accepted based only on the purchase order description even though the applicable specification contains acceptance criteria that need to be checked.
The MTR cannot be reliably traced to the heat, lot, batch, or material actually received.
The organization cannot explain which raw materials are considered significant operational risks.
A validation process exists on paper but is not performed at the defined frequency.
Independent testing or laboratory validation results are not reviewed when they conflict with supplier documentation.
Personnel performing MTR evaluations do not have access to the information needed to determine whether the results are acceptable.
These problems can create more than an audit finding. Weak MTR controls can allow nonconforming or incorrectly represented material to enter production, creating traceability, product-safety, customer, and compliance risks.
Organizations that need help reviewing supplier controls, receiving verification, material traceability, or other aerospace QMS requirements can use AS9100 consulting services to identify gaps and strengthen the processes that support certification and ongoing audit readiness.
Frequently Asked Questions
Do we have to verify every material test report for AS9100?
If your organization uses external-provider test reports to verify product conformity, you need a process for evaluating the report data to confirm that applicable requirements are met. AS9100 does not prescribe one universal sampling ratio for all organizations. Additional validation of test-report accuracy is required when raw material has been identified as a significant operational risk, with the method and frequency determined by the organization.
When does AS9100 require us to validate the accuracy of a material test report?
Accuracy validation is required when the customer or organization has identified raw material as a significant operational risk. The validation may be performed internally or by an appropriate external source, and the organization should define a method and frequency that are suitable for the risk, material, customer requirements, and product requirements.
What will an AS9100 auditor look for when reviewing our MTR process?
An auditor may look for evidence that test reports used for product verification are actually evaluated against applicable requirements, that received material is traceable to the correct report, and that the organization's defined controls are followed. For significant-risk raw material, the auditor may also review how the organization validates test-report accuracy and responds when validation identifies a discrepancy.
Can we rely on a supplier's material test report without doing our own laboratory testing?
In many cases, independent laboratory testing is not automatically required for every material or every report. The organization still needs an effective process for evaluating test-report data when the report is used for verification. When raw material presents a significant operational risk, however, the organization must also have an appropriate process to validate the report's accuracy.
Conclusion
Auditing Material Test Reports under AS9100 is ultimately about proving that the organization's receiving and supplier-control processes can reliably confirm material conformity. A compliant process should connect the MTR to the material received, evaluate the relevant test data against applicable requirements, and apply additional accuracy validation when significant operational risk makes it necessary.
If your organization needs help strengthening Material Test Report controls, supplier quality processes, or overall aerospace certification readiness, My ISO Consultants provides AS9100 consulting services to help aerospace organizations identify practical gaps, improve process controls, and prepare for AS9100 certification and surveillance audits.
