Quality assurance and quality control – what's the difference?
|Much the way a watch's components must be perfectly arranged to provide us with an accurate measurement of time, many pieces must come together to ensure that quality work is done at Fermilab. Quality management aids in the achievement of desired results. Photos: StoneLeaf (left) and Chris Roach (right)
Many people use the terms quality assurance (QA) and quality control (QC) interchangeably. But each has a different meaning and, together, they make up a quality management (QM) system. For the mathematicians in the crowd, QA + QC = QM. At the highest level, QA is proactive and attempts to prevent problems, while QC is reactive and attempts to detect problems while fabricating a product or providing a service.
Quality assurance focuses on developing a systematic approach to activities, one that will help us avoid problems and deliver an end product that meets the expectations of our customers. Examples of QA are using qualified workers, following an accepted design process, procuring appropriate materials and services, controlling materials, following written procedures, investigating failures, documenting and applying lessons learned, and auditing work processes. Fermilab's Quality Assurance Program is in line with the DOE QA Order 414.1D. Our Integrated Quality Assurance Program defines the elements of our approach to QA at Fermilab.
Quality control, on the other hand, focuses on verifying the quality of our deliverables and aims to control outputs by performing inspections, tests and validations to determine whether or not design specifications have been met.
If all we did was QA, we would have what looks and sounds like a great set of processes and documents, but we would never actually test, check or measure the product or service to verify that it actually does what it is supposed to do.
If all we did was QC, we would be constantly checking, measuring and testing our services, widgets or research results without making any effort to improve our processes. Even if we were to find something that failed or did not meet specifications, with a QC-only approach, we would not do anything to understand problems we found when testing or attempt to eradicate those failures.
In either case, the service or product would be unlikely to meet our customers' needs and expectations.
We've always had QA and QC elements integrated into our work processes. Implementing a quality management system approach that includes both the QA and QC aspects provides a framework to articulate our work processes, clearly define system performance specifications and use measurement and testing criteria to minimize scrap, waste, schedule delays and outright failures.
Using the integrated approach, our aim is to produce exceptional end products and services that allow us to make the best use of our available resources and achieve our ambitious research goals.
—TJ Sarlina, quality assurance manager