According to Nielsen Norman
Quality assurance impacts the user experience: when things don’t work, users question their understanding and develop superstitions and inefficient workarounds.
Quality assurance (QA) and user experience (UX) have a two-way relationship:
Most obvious, usability is a quality measure for design. To ensure usability, a good UX thus requires QA thinking.
Beyond the user interface itself, many other quality issues also impact the total UX.
Usability as QA
First Law of Usability: Your design will be tested by users — your only choice is whether to run the test yourself before launch so that you can fix the inevitable problems while it’s cheap instead of playing expensive catch-up later.)
Quality Assurance on the web, often referred to as QA, is a proof and review of a product or deliverable - in our case web applications and websites. QA is independent of the design and development processes in order to test a product’s many uses in the myriad of ways an enduser, especially those unfamiliar with the software, might. The QA process is expected to discover design issues and development errors while testing a product’s user interface (UI) and gauging the user experience (UX).