Working With NATA Assessors: What Laboratories Should Know

For many laboratories, a NATA assessment is one of the most anticipated and, at times, stressful parts of the accreditation process.

There is often uncertainty about what assessors will focus on, how interactions will unfold, and what constitutes a “good” assessment outcome.

In practice, most assessments are far more straightforward than expected. The challenges that arise are rarely due to hidden technical requirements, but rather from unclear systems, inconsistent practices, or misunderstandings about what is being assessed.

In Part 1 of our Accreditation Readiness series, we wrote about What Laboratories Actually Need to Know about accreditation to ISO/IEC 17025.

This article outlines what laboratories should expect when working with NATA assessors, and how to approach the assessment process in a calm and constructive way.

NATA assessors evaluate whether a laboratory can demonstrate technical competence, valid results, and controlled processes under ISO/IEC 17025. They assess systems in practice, not just documentation.

What NATA Assessors Are Actually Evaluating

NATA assessments are conducted against ISO/IEC 17025, ISO 15189 or ISO 17020, but they are not simply clause-by-clause reviews.

Assessors are evaluating whether your laboratory can demonstrate:

• Technical competence

• Valid and reliable results

• Controlled and consistent processes

• Awareness and management of risks

• Effective response to issues

Importantly, this is assessed through evidence in practice.

Documentation supports this process, but it is not the primary focus. Laboratories that concentrate on producing perfect documents often find that gaps emerge when assessors explore how work is actually performed.

Common problem areas on assessments and post-assessment

Equipment calibrations

For years, you were minding your own business and doing as NATA says for equipment calibrations.  

But now they tell you that you might have to work out your own calibration frequencies and ‘prove’ that they are suitable. To add insult to injury, you’ve been told that calibrations on basic lab equipment like pipettes and volumetric glassware (that you’ve been doing since starting work in a lab), have never been done properly and you have to pay someone else to do them!

This doesn’t mean that lab staff are suddenly incompetent when it comes to performing something as simple as a pipette calibration.

However, a good understanding of the sources of uncertainty in your methods (including your calibration methods) will help. You can make decisions about which equipment can be calibrated in-house and which ones really do need an expert hand.

One of our clients calculated the uncertainty budget for their pipette checks, and it was better than the external calibration that NATA was demanding. And it was traceable.

Getting to know your methods intimately by calculating measurement uncertainty (MU) properly will help you stand your ground and explain how your lab does meet the requirements for traceability in measurements.  You will also have the evidence to show NATA and back your decisions on:

• competency assessments and training programs
• conducting equipment checks in-house or sending out for calibration
• purchasing new equipment
• improving method performance.

You can pull out the GUM, the Eurachem/CITAC Guide, the instructions from your professional body, or the notes from that course you went to and give it a go.

But, MU is only a part of the picture. Proving you have a traceable measurement is the other piece. Knowing this important part of your lab’s results is another key to making the NATA assessors happy.

We have proven methods to demonstrate the metrological traceability of your measurements to NATA assessors. You can contact us, and we can help you work through the MU and metrological traceability of your results. We can also run training courses on MU or Traceability for you and your people!

Root cause analysis

Of course, you know how to do a root cause analysis (RCA)! You’ve probably got a lovely system all set up and ready to go. Accreditation bodies have been making this a part of the post-assessment process for dealing with conditions for accreditation, so it’s an even more vital part of your system.

The tricky part here is ensuring you’ve drilled down to the REAL root cause (or causes) and implemented corrective action that will solve the problem.

And remember, you need to document this process in line with the procedure laid out in your quality documents.

Our article on root cause analysis could help you ensure you’re on track. Even better would be attending our RCA training course!

Risk management

There is an increased focus on risk management across all the ISO standards.

Of course, risk influences every aspect of your business operations. That’s why having an effective risk management approach makes good sense.

We’ve written previously about risk management and examined how risk and opportunity can go hand in hand.

Remember, you need to demonstrate to your Accreditation Body that you’ve considered risks and opportunities and your processes for dealing with these. And yes, we have a training course for this too…

 

Competence

Labs use ISO/IEC 17025, ISO/IEC 17020 and ISO 15189 to implement a quality management system (QMS), with the goal of improving their ability to produce consistently valid and reliable results.

If you follow the requirements of the Standard, you’ll have only trained, skilled and authorised staff performing lab tasks. Those staff members must prove they know how to follow procedures, perform testing or calibration activities. They must be able to perform them correctly despite any errors or omissions in documented procedures. And they should be able to handle any problems that may arise.

Ensure your staff have the appropriate training. Make sure their training information and authorisations are documented and current. Don’t forget to include any internal training on special processes or equipment.

Reporting

Customers will use the report you submit as the basis for a decision. And by having an appropriate system in place you’re giving customers the confidence that the results they receive are consistent and repeatable.

There is natural variation in results due to the nature of testing. Your lab puts controls in place to reduce this range of variation. Evaluating the MU supports the validity of your results and provides information on this natural variation.

Sometimes this information is provided in the final report. This additional detail demonstrates your lab’s capacity to detect and evaluate errors and adds relevance to your report.

If you include your Accreditation Body’s endorsement on your report this must be correct. Add the tagline and additional wording if this is required. For example, the NATA tagline is ‘World Recognised Accreditation’ (check the NATA Rules for any additional wording you may need to use).

Finally, if you’re carrying out tests for which you’re not accredited, don’t include these results on an endorsed report.

Customers first

While this may seem obvious for quality management system standards, ISO/IEC 17025, ISO/IEC 17020 and ISO 15189 have an emphasis on keeping the customer in mind.

Obviously, labs consider their customers and their needs. However, the standard requires labs to keep customer needs at the forefront of their minds throughout the testing process.

Customers should expect confidentiality. They should have an option to express any concerns they may have about the lab’s work. The lab must also confirm that it takes these concerns seriously and will investigate any issues, keeping the customer informed of the progress and outcome.

Building trust with the customer through excellent service and prompt feedback doesn’t just make sense for labs. It makes good sense for all businesses.

Keeping your business processes and procedures up to scratch isn’t just about making sure your next NATA assessment goes well. It’s about maintaining those systems to ensure you’re working better and smarter.

 

FAQs

What do NATA assessors actually look for?

NATA assessors are evaluating whether your laboratory can demonstrate technical competence, produce valid results, and operate under controlled conditions in line with ISO/IEC 17025.

They are not looking for perfect documentation. They are looking for evidence that your systems work in practice, that staff understand their roles, and that results can be trusted.

How should we prepare for a NATA assessment?

Preparation should focus on clarity and consistency rather than volume of documentation.

Laboratories should:

• review recent work and trace evidence through the process

• confirm staff competence and authorisation

• ensure equipment, methods, and quality control are well managed

• review corrective actions and previous findings

A calm, structured review is far more effective than last-minute document updates.

Do assessors expect staff to know ISO 17025 clauses?

No.

Assessors are not testing whether staff can recite the standard. They are assessing whether staff understand their work, follow procedures, and can explain how they ensure valid results.

Confidence and clarity are far more important than memorisation.

What is the most common mistake laboratories make before an assessment?

One of the most common mistakes is overcomplicating the system just before the assessment.

Introducing new procedures, rewriting documents, or adding layers of control at the last minute can create confusion and increase risk. Stable, understood systems are always stronger than newly “polished” ones.

How do NATA assessments differ from internal audits?

Internal audits are conducted by the laboratory to review its own system. NATA assessments are independent evaluations of competence and compliance against ISO/IEC 17025.

Assessors will typically go deeper, follow evidence across processes, and test how systems operate in practice rather than just reviewing documentation.

What happens if we receive nonconformances?

Nonconformances are a normal part of the assessment process and do not necessarily indicate failure.

What matters is how they are addressed. Laboratories are expected to:

• identify the root cause

• implement appropriate corrective actions

• demonstrate that the issue is controlled and unlikely to recur

Thoughtful, proportionate responses build confidence with assessors.

How should we communicate with NATA assessors during the assessment?

Communication should be professional, clear, and factual.

It is appropriate to:

• provide evidence when answering questions

• clarify context where needed

• acknowledge uncertainty if you do not know something immediately

Defensive responses are rarely helpful. Open, constructive engagement is far more effective.

How long does a NATA assessment take?

The duration depends on the size and complexity of the laboratory’s scope.

Assessments may range from one day for small, focused scopes to several days for larger or multi-disciplinary laboratories. The key is not the duration, but the ability to demonstrate consistent control across all activities.

Can we fail a NATA assessment?

Assessments are not typically framed as pass or fail.

However, significant or numerous nonconformances can delay accreditation or require further review before approval is granted. Laboratories that demonstrate competence, control, and a willingness to improve generally progress successfully through the process.

What is the best way to feel confident before an assessment?

Confidence comes from understanding your system, not from trying to perfect it.

If your laboratory can:

• explain how work is controlled

• demonstrate competence

• show how issues are managed

then you are in a strong position for assessment.

We can help!

If your next assessment is approaching and you want an objective view of your readiness, we are here to support you!

We can help you unclog your systems and keep them running smoothly. Also, we have training to support your people and your business.
Email info@masmanagementsystems.com.au or phone Maree on 0411 540 709.

Remember, you don’t have to do this alone!

 

Catch up on our Accreditation Readiness series:

Part 1: ISO/IEC 17025 Accreditation: What Laboratories Actually Need to Know

Part 3: How to Prepare for an ISO 17025 Assessment (Without the Panic)

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