Longman Dictionary of Contemporary English
n. A system in which the delivery of a service or the quality of a product is assessed, and compared with that required.
Quality assurance (QA) is a way of preventing mistakes or defects in manufactured products and avoiding problems when delivering solutions or services to customers; which ISO 9000 defines as "part of quality management focused on providing confidence that quality requirements will be fulfilled". This defect prevention in quality assurance differs subtly from defect detection and rejection in quality control, and has been referred to as a shift left as it focuses on quality earlier in the process.
Quality assurance comprises administrative and procedural activities implemented in a quality system so that requirements and goals for a product, service or activity will be fulfilled. It is the systematic measurement, comparison with a standard, monitoring of processes and an associated feedback loop that confers error prevention. This can be contrasted with quality control, which is focused on process output.
Two principles included in quality assurance are: "Fit for purpose" (the product should be suitable for the intended purpose); and "right first time" (mistakes should be eliminated). QA includes management of the quality of raw materials, assemblies, products and components, services related to production, and management, production and inspection processes.
Suitable quality is determined by product users, clients or customers, not by society in general. It is not related to cost, and adjectives or descriptors such as "high" and "poor" are not applicable. For example, a low priced product may be viewed as having high quality because it is disposable, whereas another may be viewed as having poor quality because it is not disposable.
Usage examples of "quality assurance".
How could TRX and AeroTech's checks and double checks and Quality Assurance programs all go south at precisely the same time?
The next building along bore the label quality assurance BRANCH, CHIEF.
Lester Van Slyke worked as a quality assurance engineer for Boeing in Seattle.
Li Zedong had been the Director of quality assurance on the program.
The buildings inside the front gate are administrative offices, and the ones behind, quality assurance and research labs.
What was the mix of parachute types to be procured commercially, checked through the USAF internal quality assurance process, and shipped (packed or unpacked based on circumstances) to meet Korean Theater needs in a combat environment and rapid changes in the Theater's types of aircraft?