In developing products and services, quality assurance is any systematic process of checking to see whether a product or service being developed is meeting specified requirements. Many companies have a separate department devoted to quality assurance. A quality assurance system is said to increase customer confidence and a company's credibility, to improve work processes and efficiency, and to enable a company to better compete with others. Quality assurance was initially introduced in World War II when amunitions were inspected and tested for defects after they were made.
Today's quality assurance systems emphasize catching defects before they get into the final product. Various quality systems came into existence for improving quality standards in processes and products.
The International Organization for Standardization (ISO) defines a standard as a "document, established by consensus and approved by a recognized body, that provides – for common and repeated use – rules, guidelines or characteristics for activities of their results, aimed at the achievement of the optimum degree of order in a given context.“