ISO 17025 in automotive – from measuring equipment to measurement uncertainty

Why is ISO 17025 becoming increasingly important in the automotive industry? More and more organizations are asking the same question: is our measurement laboratory truly reliable? OEMs and Tier 1 customers no longer expect measurement results alone. Above all, they expect evidence that these results are reliable, repeatable, and defensible during an audit or a customer claim.

In practice, it all comes down to the credibility of quality decisions based on test results. That is precisely why more and more automotive organizations are turning to ISO 17025. This standard addresses the competence of testing and calibration laboratories. In other words, it helps structure the entire measurement system—from equipment and measurement methods to the management of measurement uncertainty.

Why is ISO 17025 important for automotive laboratories?

ISO 17025 is an international standard that specifies requirements for the competence of testing and calibration laboratories. However, in the automotive industry, its relevance is particularly strong.

On the one hand, organizations operate within a management system certified for compliance with IATF 16949. On the other hand, they must ensure the full credibility of measurement data, which often determines whether a product can be released for serial production. Importantly, ISO 17025 accreditation can be used as evidence of meeting these requirements. However, it is not always mandatory.

For many organizations, ISO 17025 is a natural extension of requirements already known from IATF 16949, especially in the areas of:

• management of measurement equipment
• metrological traceability
• validation of test methods
• personnel competence
• analysis of measurement uncertainty

What laboratory requirements does IATF 16949 set?

Laboratory requirements are included in section 7.1.5.3 of the IATF 16949 standard. IATF defines a laboratory as:

Laboratory – a location for inspection, testing, or calibration that can perform, among others: chemical, metallurgical, dimensional, physical, electrical, or reliability testing.

The standard distinguishes two types of laboratories:

• internal laboratory,
• external laboratory.

In the case of an internal laboratory, the organization must ensure, among other things:

• adequacy of technical procedures,
• personnel competence,
• capability to perform product testing,
• metrological traceability to appropriate standards,
• consideration of customer requirements,
• review of laboratory records.

It is also worth emphasizing that IATF 16949, recognizing that ISO 17025 introduces additional requirements, includes the following note:

Third-party accreditation to ISO 17025 may be used to demonstrate the organization’s in-house laboratory conformity to this requirement.

If the organization uses an external laboratory, that laboratory should have ISO 17025 accreditation issued by an accreditation body that is a signatory to the ILAC MRA. In addition, the scope of accreditation should cover the relevant inspection/test/calibration, and the report or certificate should include the accreditation body’s mark.

Otherwise, the organization itself must demonstrate that the laboratory meets requirements equivalent to those for internal laboratories.

Measurement equipment in the laboratory under ISO 17025

In many companies, a laboratory is equated with a list of measuring instruments. Then the organization focuses mainly on the calibration schedule (if calibration is within the laboratory’s scope).

However, that is only part of the system.

ISO 17025 emphasizes that equipment management is not only about having the equipment, but also about controlling conditions, methods, and traceability of results. In other words, the equipment must deliver results you can trust.

In practice, it is worth controlling:

• equipment identification and its status (e.g., approved, on hold, after repair),
• technical condition monitoring and response to damage,
• validation of measurement methods for specific applications,
• control of environmental conditions (temperature, humidity, vibration),
• traceability of measurement results to appropriate references.

Laboratory personnel competence

You can buy equipment. You cannot buy competence.

That is why one of the key requirements of ISO 17025 is managing the competence of laboratory personnel. Moreover, IATF requires the laboratory to demonstrate people’s competence, which is directly linked to the effectiveness of laboratory services.

The laboratory should clearly define:

• competence requirements for roles (e.g., performing the test, approving the result),
• the training and onboarding process,
• authorization of personnel to perform specific methods,
• periodic competence assessment and re-authorization.

In audit practice, the same pattern appears again and again: an operator measures according to the instruction, but does not understand the method’s limitations. Consequently, the result is interpreted as an “absolute truth” rather than information burdened with measurement risk.

Measurement uncertainty in ISO 17025

Measurement uncertainty is one of the most demanding elements of ISO 17025. At the same time, in many organizations, it remains only a formal entry in a procedure.

Why is it so important?

Measurement uncertainty answers a critical question: how far can the measurement result deviate from the true value? Every measurement carries a certain error, because every result is an approximation of the true value. If you do not know the uncertainty, you do not know how wide that approximation is. And if you do not know that, you make quality decisions based on data of unknown reliability.

Uncertainty is influenced by, among others:

• instrument accuracy and resolution,
• stability of the measurement method,
• environmental conditions,
• operator influence,
• stability of the measured object,
• sample preparation method and measurement time.

As a result, failing to work with uncertainty can lead to:

• incorrect conformity assessment (false accept or false reject),
• unnecessary sorting and scrap costs,
• customer disputes, because results do not “match” between parties,
• audit nonconformities due to the lack of a consistent approach to conformity decisions.

Therefore, it is worth treating uncertainty not as an “ISO 17025 obligation,” but as a tool to reduce business risk. In other words, it is a practical language for discussing whether a given measurement can support a decision.

ISO 17025 vs. MSA – isn’t MSA enough?

MSA is a very important tool and remains one of the key AIAG / VDA Core Tools. However, its main purpose is to assess whether the measurement system is suitable for monitoring a production process. ISO 17025 has a slightly different purpose.

It focuses on:

• laboratory competence
• method validation
• metrological traceability
• uncertainty analysis

In short, you could say:

MSA answers whether the measurement is good enough to control the process. ISO 17025 answers whether the measurement result is scientifically reliable.

In practice, both approaches should complement each other rather than replace one another.

Does ISO 17025 accreditation solve every laboratory problem?

In many organizations, there is a belief that ISO 17025 accreditation automatically solves every problem. However, it works only when accreditation is not the goal in itself.

Accreditation confirms that system requirements are met. However, the most important element remains quality culture and real management of measurement data.

Therefore, an effective automotive laboratory should go beyond the IATF 16949 framework and should:

• understand the role of measurement data in decision-making (not only during audits),
• manage personnel competence in a measurable way,
• analyze and use measurement uncertainty in conformity assessment,
• ensure metrological traceability through appropriate references and control,
• regularly review records and draw conclusions from deviations.

Only then do test results become a reliable foundation for quality decisions. And consequently, this translates into fewer customer disputes, lower cost of poor quality, and a calmer audit.

FAQ

Does an internal laboratory have to be accredited to ISO 17025?

No. Accreditation is not mandatory. However, the organization must demonstrate that the laboratory meets the IATF 16949 requirements for internal laboratories, including adequate procedures, personnel competence, metrological traceability, and review of records.

Does every external laboratory have to be ISO 17025 accredited?

An external laboratory should have ISO/IEC 17025 accreditation (or an equivalent national accreditation) within the relevant scope, issued by an accreditation body that is a signatory to the ILAC MRA. If an accredited laboratory is not available, the organization must have evidence that the laboratory has been evaluated against the requirements for an internal laboratory.

Why is measurement uncertainty so important in automotive?

Because product conformity decisions often rely on measurement results. Without knowing the measurement uncertainty, it is difficult to reliably assess result credibility and the risk of a wrong decision (false accept or false reject).

Does calibrating an instrument mean the measurements are reliable?

Not necessarily. Calibration is only one element of the measurement system. Result reliability also depends on the measurement method, the operator, environmental conditions, and how the result is interpreted with measurement uncertainty taken into account.

Need support in metrology for the automotive industry?

If questions arise in your organization about ISO 17025, MSA according to AIAG or VDA, measurement uncertainty, calibration, or measurement equipment management, you are not alone. In many automotive companies, these areas are among the biggest challenges during customer audits and certification audits.

At QualityWise®, we help automotive organizations structure measurement systems so they are reliable, compliant with IATF 16949 requirements, and ready for ISO 17025 expectations.

Our metrology trainings and workshops include, among others:

• Measurement System Analysis (MSA) – practical implementation aligned with AIAG & VDA
• Measurement uncertainty in automotive laboratories – how to calculate and interpret it correctly
• ISO 17025 for internal laboratories – a practical approach for the automotive industry
• Measurement equipment management
• Metrology – length and angle measurements
• Calibration of length and angle measuring instruments

📩 If you want to strengthen metrology competence in your organization or prepare your laboratory for an audit – contact us.

Summary

An automotive laboratory is not just a place where tests are performed. In reality, it is part of the quality management system that provides data for key product decisions. Therefore, ISO 17025 and IATF 16949 focus not only on equipment, but above all on:

• competence,
• technical procedures,
• metrological traceability,
• measurement uncertainty analysis.

Organizations that treat the laboratory merely as a support function will sooner or later face problems during audits or in customer relationships. In contrast, companies that understand the role of the measurement system build a real quality advantage.

PhD Eng. Agata Lewkowska

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