From our perspective, quality assurance is a subset of the overall usability goal after all, a website isnot usable if it is not working.
Quality assurance is an important step in the website development process and, by all means, should not be skipped. A broken link or a misspelled word may seem like trivial mistakes, but they can greatly undermine the credibility of your website. You want people who visit your site to feel confident about the quality of the information they find.
Your company should come up with its own set of guidelines to follow while conducting quality assurance testing. The guidelines should address editorial, graphics, and coding conventions. After the site has been built, it should be put through a rigorous post-production process. Finally, there should be a provision for user feedback, which can influence the ongoing maintenance of the site.