What to Do in an NDT Audit

by Bruce Crouse

Nondestructive testing audits are increasingly prevalent in all sectors of NDT. The manufacturing of refineries and aircraft, for example, requires many support companies manufacturing components for the completion of a project. To verify that components meet contract requirements in dimension and quality, companies will send auditors to review quality during the manufacturing process. Some of the duties of auditors are to verify that the company NDT procedure aligns with the customer requirements and to witness technicians performing inspections to those requirements.

Audits have been conducted for years and they have become more sophisticated over time. While audits and auditor training have become more involved, audit training for NDT technicians has often lagged. Management has focused on quality managers attending training classes on audit process and passing that information on to technicians. Technicians often receive that training just before the audit with directions to “do what you normally do,” which can lead to technicians learning the audit process by doing.

The Audit Process

Recommended Practice No. SNT-TC-1A does not list qualification training for auditors, however, auditors may use SNT-TC-1A to verify that the requirements of the company’s written practice are being followed and documented. The auditor will verify alignment of the company inspection process document with customer requirements as well. Auditors trained in the audit process most often will follow a checklist while performing an audit.

Terms used to identify conditions that do not align with the customer requirements are called findings and corrective actions. When the auditor locates an area in the auditee’s document that is not in alignment with requirements, the auditor records this as a “finding.” A finding will require a “corrective action” to be issued. The auditee, at a minimum, will then be required to investigate and report why the error has occurred, what will be done to correct the problem, and how it will be verified so it will not occur again.

Unfortunately for the auditee, this may only be the beginning—the auditor often will evaluate that particular area in greater detail, possibly requiring reports, support documents, or other materials for review. Examples of this would be a finding that calibration of a light meter or gauge is not current. If it is discovered a light meter is out of calibration and is in use by the technician, the auditor may want to verify that the calibration is current on all equipment requiring calibration, going back a year or more. This can extend the audit and can present a problem if it is discovered that other equipment had not been calibrated as it should have.

Typically, findings fall into two classes: major and minor. A “major” finding could cause the company to fail the audit. Technician mistakes made processing components during the audit often are considered major findings, meaning missing a defect would be an example of “product impact.” The question in the mind of the auditor then becomes—is this finding an indication the technician may have missed discontinuities on other items that are in stock or have been delivered to the customer?

A “minor” finding is less likely to cause product impact and will not typically result in failure of the audit. However, if a number of minor findings are made, they could result in failure. An example of a minor finding would be the company procedure not listing the number of hours of classroom and on-the-job training required before certification. If the auditee can document that the company understands and has completed all of the training required by SNT-TC-1A, the auditee will be issued a minor finding and be required to address this in the written practice.

Common NDT Technician Mistakes

For individuals with little experience or training, audits can be stressful. If a number of findings or nonconformities are found when the technician is processing and inspecting components, it could mean the loss of a customer’s business or a product recall. Either situation can result in an economic burden for the company.

During an audit, technicians may tense up and overcompensate, occasionally making mistakes they would not normally make. The cure for all this is training and “time on task”; that is, as technicians become accustomed to the audit process fewer “mistakes” are made. Recognizing this, some companies incorporate audit training as part of NDT classroom training. Recommended Practice SNT-TC 1A section 10.0 “Technical Performance Evaluation” provides an opportunity for a company to provide technicians with training and an understanding of the audit process. This section states the review is to be periodic but does not specify annually. I would suggest the evaluation be performed annually, where the supervisor reviews the technicians’ performance processing components in a formal setting as would be found in an audit. A review of past audit findings in the method at the company would also be helpful at that time.

Here are some common mistakes I have witnessed technicians making over the years.

Talking with Auditors

Talking is distracting and can lead to inadvertent mistakes by the technician. Auditors typically discourage discussion, but often technicians volunteer information or initiate discussions during the audit. Technicians should be cordial and answer all questions but should not provide any additional information.

Failure to Locate and Review Procedures, Codes, and Specifications

Another common mistake is not reviewing the applicable procedure, code, or specification before performing an inspection for the auditor. Technicians often work with multiple specifications for a given method. Many manufacturers use ASNT and ASTM documents as the base processing documents for the company. In a given method, process requirements are often similar from customer to customer, however, subtle changes can occur. Dwell time in liquid penetrant inspection would be a good example. Dwell times of 10 min minimum are common; however, occasionally a customer will extend the time. If documents are not reviewed before or during the inspection, mistakes can be made, resulting in a finding.

Whether it is for production inspection or during an audit, inspectors who do not stop and review information when there is a procedural question are positioning themselves for trouble. Best practices require inspectors to have current revisions of documents available during inspections and while processing. It is a common practice to have a folder containing all needed inspection documents available on the technician’s computer during an audit.

In one example I witnessed during an audit, an inspector made an obvious processing mistake but did not realize it. As the inspection continued, the auditor asked a question that should have caused the technician to think about verifying his processing. Whether it was the result of nervousness or a fear that he would look less than competent if he checked the procedure, the technician continued and received a finding.

Another aid technicians may have access to during an audit is their Level III who they can ask for clarification or directions. Level III individuals typically attend audits and are always a resource that the technician can use.

An example of what not to do during an audit occurred when a liquid penetrant inspector proudly proclaimed that he had developed a better way to perform the inspection than what was required by the customer. He then proceeded to demonstrate it to the auditor. When finished, the auditor requested the inspector locate the processing requirements in the customer procedure and issued a major finding as a result of the technician’s actions. The Level III was included in the finding for not maintaining oversite of the individual.

Technicians performing visual inspections often have procedural requirements stating the inspection area is to have 100 fc of white light at the inspection surface during the inspection. When questioned about this requirement, I have frequently received one of the following responses from technicians:

• The company has a light meter, but we do not use it because it is not calibrated.
• The company has a light meter, but it is in another department at this time

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If the procedure states white light will be measured, then there must be a way to measure it. The technician should be aware of the requirement and insist to management that the meter is available and calibrated. If the procedure calls for the use of such an instrument, it must be used.

Failure to Allow Eye Adaptation

Failure to allow the eyes time to adapt to a darkened area is a common mistake made during a fluorescent penetrant or magnetic particle testing audit. While technicians will allow their eyes to adapt initially, they often fail to readapt after briefly stepping out of the booth or turning on a white light to review an area of the part. LED lights can have a switch that will allow the technician to turn on a white light during the inspection. This is helpful, but technicians tend to use the light and not readapt their eyes.

Control of Inspector Stamps

Lack of control of inspector stamps can be a simple audit finding. Documents require that technicians maintain control of stamps at all times. Auditors often find stamps openly stored in areas inspectors use to complete paperwork. If not in the technician’s possession, inspector stamps should be locked away.

Conclusion

Audits have been a positive force in all industry sectors elevating procedural documents available to the inspector, inspector awareness of process, and quality requirements for performing inspections as well as for maintenance and use of support equipment such as gauges and inspection instruments. The purpose of any audit is to confirm the correct process documents are used and are followed.

Audits often reveal shortfalls within the system and processing applications. Though this can result in uncomfortable situations, both NDT inspection companies and inspectors can use the audit results as an opportunity to improve quality and develop technical skills and knowledge.

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Bruce Crouse is the owner of Inspection Services Nondestructive Testing, LL.

To assist personnel preparing for NDT audits, ASNT publishes audit checklists for both Recommended Practice No. SNT-TC-1A and ANSI/ASNT CP-189.

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The SNT-TC-1A Audit Checklist covers the minimum requirements in SNT-TC-1A and is intended to help companies prepare for the audit of NDT personnel training, qualification, and certification. It provides a useful checklist for the review of a company’s written practice before an audit. Based on the recommendations in SNT-TC-1A (2020), the checklist covers only the auditable paragraphs and sections in the recommended practice. Paragraphs that are not part of an NDT audit are not included, and paragraph numbers may be skipped. Because SNT-TC-1A is a recommended practice, employers may certify methods and limited certifications not listed.

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The CP-189 Checklist covers the specific procedures, essential factors, and minimum requirements for qualifying and certifying NDT personnel to this standard.