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QC Failures Happen

Methods for determining which undesirable conditions require root cause analysis and which do not.

by Ned Gravel
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Quality management systems (QSM) have been a reality in nearly 4,000 North American laboratories for some time. Almost everyone has heard of a quality system. Many relate the term to ISO standard ISO 9001:2008. However, for laboratories the more appropriate standard that defines laboratory, quality systems is ISO/IEC 17025:2005: General requirements for the competence of testing and calibration laboratories. This standard focuses primarily on the technical validity of laboratory results.

ISO/IEC 17025 provides all the tools that a laboratory should have in place in order to demonstrate that it can consistently produce technically valid results. Laboratories that provide such demonstration to an accreditation body can then be accredited to ISO/IEC 17025 by that accreditation body.

Since the first publication of ISO/IEC 17025 to replace ISO/IEC Guide 25 in 1999, the laboratory industry has demonstrated substantial improvements in the quality (consistency) of laboratory results. This progress can be directly linked to the quality assurance, quality control, and quality management system tools contained in specifications such as ISO/IEC 17025.

One of the best quality system tools in a laboratory’s arsenal is the good and reasoned approach to handling the things that go wrong in the lab. This includes the determination of what actually caused the problem, to ensure that it does not recur. This tool is called corrective action if the problem has already occurred, preventive action when it has not yet occurred, or continual improvement to capture both in one holistic system.

Regardless of when the problem occurs (or may occur), the starting point for both preventive and corrective action is the analysis of root causes of the problem. Good root cause analysis normally involves:

  • correctly identifying the undesired condition,
  • determining the immediate and intermediate causes of the undesired condition, and finally,
  • determining the root or underlying cause of the undesired condition.

More than any other laboratory quality system tool, root cause analysis provides clarity on the real issue that underlies a problem. If the underlying issue is not addressed, it is very likely that the problem will recur and impede the production of technically valid results.

There are some simple approaches available to determine root causes. They are objective and based on developing an understanding of the issue, its environment, the science, and the organization involved. However, few laboratory quality system practitioners can identify objective criteria that can determine if full corrective or preventive action is needed, along with the concomitant root cause analysis, and that is the reason for this article. In fact, root cause analysis is not needed to effectively address all undesirable conditions. What follows here is a method of determining which undesirable conditions require root cause analysis and which do not.

Root cause effort

First, it is important to understand that the ISO definition of nonconformance (nonconformity) comes from ISO 9000:2005. Clause 3.6.2 defines it as nonfulfillment of a requirement, where the requirement can be any written specification such as an instruction, a procedure, a set of limits to meet, or even a regulation. Whenever a condition does not meet a requirement, nonconformance has occurred. Just to show how far this concept can go, not finishing sentences with a period could be considered nonconformance.

So which nonconformances need root cause analysis?

The short answer is: all those that impede the laboratory’s ability to produce only technically valid results or create an unacceptable level of risk to the organization, its people, or other stakeholders.

These are simple and objective considerations. Combined with a third consideration that compares the effort for permanent resolution with the effort for repeated correction, any laboratory can implement objective criteria in determining the necessity for root cause analysis.

Root cause analysis can involve a lot of individual and laboratory energy and effort, and for this reason some managers and supervisors are reticent to implement it as a matter of course. As a result, shortcuts may involve blaming a person for having made a mistake (nonconformance). This is often deemed sufficient root cause analysis and the solution selected to solve the problem can range from a verbal warning to actually firing the person who made the mistake. Neither of these approaches demonstrates understanding of quality systems or root cause analysis.

ISO/IEC 17025 already describes the tools for labs to demonstrate their competence in that the lab has:

  • the people with the requisite skills and knowledge;
  • the required environment, including the facilities and equipment;
  • the required quality control and quality assurance; and the required procedures…to produce technically valid results.

None of these objective criteria have anything to do with a person “making a mistake.” They all have to do with the laboratory quality system’s ability to help the laboratory consistently produce technically valid results.

When this is understood, it is possible to objectively determine if root cause analysis is actually needed whenever a nonconforming condition (the problem) is encountered. Such determinations can be objective and fact based, depending on the objective answers to three simple questions.

Objective criteria to determine the necessity for root cause analysis

Whether the undesirable condition is nonconformance, potential nonconformance, or even opportunity for improvement, there are normally only three conditions that require the use of full corrective or preventive action involving root cause analysis. They are the following:

  • Does the condition cause us to have invalid (incorrect) results? Or could it?
  • Does the condition present us with unacceptable risk (to the lab, to our people, to our visitors) such as health and safety concerns?
  • Will it be easier to conduct full corrective or preventive action than it will be simply to continue to correct the situation?

If any of these questions are answered with a “yes,” then full corrective or preventive action is required, starting with root cause analysis.

Otherwise, the situation has fairly little impact on the laboratory, its people, its visitors, or its ability to consistently produce technically valid results, and it is apparently easier to just keep correcting the situation than attempt to permanently prevent its recurrence (corrective action). Corrective action and root cause analysis are not required.

Documenting the condition, however, is always required. A condition that recurs should be documented so that the laboratory can examine the impact of its continuation and make considered decisions on the value of undertaking full corrective action versus continuing to simply correct it. For example, one QC failure resulting in a rerun of the samples every six months may not be indicative of a systemic problem, while a once-per-week recurrence may indicate a problem that should be addressed.

Some laboratory approval schemes want the extra work done anyway

There are some laboratory approval schemes that will require laboratories to undertake corrective or preventive action beyond what is suggested here. For example, pharmaceutical testing laboratories approved or licensed under Food and Drug Administration (FDA) or Health Canada (HC) regimes may be required to define nonconformances and corrective actions differently than are laboratories accredited under a voluntary conformity assessment program. Often, a laboratory may have more than one set of approvals and it will select the most stringent of the requirements to implement across the whole of its quality system.

Laboratory QMSs working to ISO/IEC 17025, based on standard voluntary conformity assessment approaches, are not as prescriptive as the FDA and HC regulatory regimes on this issue, and these regulators may insist on root cause analysis for everything that is documented as a departure or nonconformance by the lab. This also raises the issue about an out-ofspecification condition—but that is a whole other topic for a later article.

As well, those laboratories approved under the Performance Review Institute NADCAP program for the aerospace industry may also be required to “do it anyway.” NADCAP no longer accredits laboratories against ISO/IEC 17025, but its requirements are still fairly specific.