Investment in Capital, Personnel, and Management Commitment is Key
In the production and service sectors, quality means “meeting the customer’s expectations.” The quality data produced by the laboratory thus needs to be accurate, defensible, and fit-for-purpose to meet the customer’s expectations.
History of quality systems
Quality is the result of good systematic management practices. The famous PDCA Cycle lists plan, do, check, and act (PDCA) as the four continuous steps to achieve quality. The PDCA cycle has also been referred to as the Deming cycle, named after Dr. W. Edwards Deming, the father of modern quality control. Dr. Deming further credited Walter Shewhart, the inventor of statistical process control and a longtime collaborator of Deming’s by referring to the PDCA (plan-do-check-act) cycle as the Shewhart Cycle. In the early 1970s, companies in the Western world started to design and develop quality management processes in manufacturing. The quality system concept further expanded to the service sectors, which includes laboratory services. Quality data production is never a static process and requires a systematic approach through continuous improvement.
Quality management and toolbox
Generally speaking, quality data is the ultimate goal of a laboratory service. The goal is achieved through implementation of a successful quality management system. The managerial and technical requirements need to be fulfilled from both top-down and bottom-up. The laboratory organization needs to provide supportive infrastructure and clearly define responsibilities for all laboratory personnel, including both managerial personnel and technical personnel. Top management’s commitment to the organizational quality policy is crucial to maintaining a sustainable quality system for the whole laboratory. Quality assurance (QA) programs and quality control (QC) are designed to uphold the quality policies and maintain and improve the laboratory quality to assure quality data production. QA and QC programs are essential components of the laboratory quality system.
Besides the QA and QC programs, the laboratory quality management system is also connected to and/or involves management of the capital, budgets, purchasing, supplies, equipment, inventories, training, and customer service. The management team needs to ensure adherence to quality polices that include the quality manual, quality assurance plan, and standard operating procedures (SOPs). Within quality assurance, there are many laboratory activities that are vital to providing accurate and defensible data. SOPs are controlled documents that describe and specify procedural details of a laboratory activity. An SOP can be issued for how to perform an analytical method to measure the chemical component in a certain sample matrix, and can also be issued to describe the procedures to purchase an instrument. Typically an SOP should follow a format that is adherent with the laboratory management system. An SOP is a controlled document that requires authorization from the responsible parties. Statistical process control (SPC) is routinely used in quality control as a decision-making tool to monitor a process in which the laboratory data is continuously produced. Monitoring and tracking change is the foundation of SPC, and the occurrence of a change initiates the quality manager or a quality specialist to start an investigation and determine, if possible, the cause of this change. The most utilized SPC tool is the control chart and to monitor the trend change in the measurement of a testing method. The mean and range calculated from multiple sets of measurements are used to determine if one set of data is out of control or not. The use of the control chart to validate whether the process is out of control or not allows for the entire analytical process to be monitored. The control chart is not able to identify the cause for the change, rather it provides a means to signal potential factors that might impact data quality. Routine reference materials and proficiency tests are also important tools for quality control and quality assurance. Reference materials provide standards to evaluate the accuracy of a measurement method and are important in method validation. Commercially available certified reference materials (CRMs) are invaluable to a laboratory in terms of method evaluation. Typically, a certificate is provided with those commercially available CRMs, reporting the assigned value along with the measurement uncertainty. Proficiency testing involves participating in an external process by enrolling the laboratory to test one or multiple sets of samples that are measured by a group of laboratories at the same time. Statistical evaluation is performed outside of the participating laboratory and results are reported to all participants. PT tests are often arranged according to a fixed schedule, with results being reported within a required timeframe.
Corrective actions are important aspects for quality assurance. Once a deficiency is found during the quality monitoring process, the laboratory needs to take action to correct the deficiency and follow up to make sure the corrective actions truly eliminate the deficiency. Personnel training and continuous improvement with sufficient documentation enable the system to track potential gaps in the laboratory quality system. In summary, appropriate documentation is the backbone of the quality assurance system.
Laboratory quality management system models
There are no standards for quality. However, there are several quality system models that a laboratory can follow and a laboratory can implement correct procedures to achieve quality. Quality system models offer standards to assess a quality system.
In 1947, the International Organization for Standardization (ISO) was created by industry, marking the beginning of global efforts for international standards. In laboratory testing, the most relevant standards are ISO 9001, ISO 17025, and ISO 15189. The ISO catalogue is generally organized by International classification of Standards (ICS) or Technical Committee (TC). Under the ISO/TC 176 quality management and quality assurance is the ISO 9001:2015 “Quality management systems-requirements”; Under ISO /CASCO (Committee on Conformity Assessment) is the ISO 17025:2005 “General requirements for the competence of testing and calibration laboratories”; Under ISO/TC 212 Clinical laboratory testing and in vitro diagnostic test systems is the ISO 15189:2012 “Medical laboratories - requirements for quality and competence.” ISO accreditation is a process in which an external laboratory accrediting body assesses the laboratory against the ISO standards and confirms that the laboratory conforms to ISO standards. It might be a common misconception that laboratory ISO accreditation can guarantee the accuracy and precision of the laboratory data. ISO accreditation does not guarantee the quality of the laboratory data but rather it substantiates the consumer’s confidence in the data quality. In a regulatory scheme for laboratory testing of something like product safety, legal language might require the testing laboratory to obtain ISO accreditation before authorizing laboratory reports for legal actions. In the United States, third-party accreditation is a common practice that is recognized by the government and industry. The International Laboratory Accreditation Cooperation (ILAC) is the international cooperation of laboratory accreditation bodies working on development and harmonization of accreditation practices. Many international or regional organizations sign into the Mutual Recognition Arrangement (MRA) with ILAC to work with similar quality objectives and offer laboratories accreditation services worldwide.
For most general testing and calibration laboratories that are not in the clinical field, ISO 17025 is the benchmark standard for accreditation. However, as a standard, ISO itself does not specify how the laboratory should implement the standards, but leaves it to the individual laboratory to fulfill the standard requirements. Accreditation bodies interpret the ISO language and work with the laboratories to obtain ISO accreditation.
Having originated in New Zealand and Denmark in 1972, Good Laboratory Practice (GLP) is currently a quality model adopted by the Organization for Economic Co-operation and Development (OECD) in 1992. GLP is more specifically designed for chemical nonclinical safety tests from physical-chemical properties to toxicity tests. The GLP model has been widely recognized by many countries globally and has been incorporated into some countries’ legislation. For example, the US FDA has written rules into the Code of Federal Regulations (21CFR58) that preclinical animal trials have to follow GLP prior to clinical studies in humans. Regardless of legislation in some countries, there are arguments that compliance with GLP regulations is not necessarily a guarantee of good science.
The essential role of a quality system in quality data production should not be underestimated. With economic globalization, the testing community is moving forward with the merging of global companies that provide laboratory testing services. Testing results have also been important subjects of international trade disputes. With the development of numerous computerized tools for laboratory data and documentation, there are new challenges and opportunities for traditional quality assurance programs. Nevertheless, quality data is not produced without a cost. Investment of capital, personnel, and management commitment is the key to ensuring laboratory quality. Besides the existence of regulatory requirements for laboratory testing in some countries, ISO accreditation also serves as a good practice to gain customer confidence. The 21st century will embrace a mature quality concept in the laboratory testing service sector.