Quality assurance (QA), which is used in both the manufacturing and service sectors of the economy, refers to the methodical measures taken to ensure that the products delivered to customers meet their contractual and other agreed-upon expectations for performance, design, reliability, and maintainability. The main goal of quality assurance is to eliminate errors and flaws in the design, development, and production of both manufactured goods like shoes and cars as well as supplied services like auto repair and athletic shoe manufacturing.