Source : Free On-Line Dictionary of Computing

quality assurance
     
         (QA) A planned and systematic pattern of all actions
        necessary to provide adequate confidence that the product
        optimally fulfils customers' expectations, i.e. that it is
        problem-free and well able to perform the task it was designed
        for.
     
        The QA of a commercial product usually involves {alpha
        testing}, where an early version of the product is tested at
        the developer's site, and is then improved accordingly.  Then,
        an almost complete version of the product is made available
        for {beta testing} by (selected) real users.  Faults
        identified during beta testing should be fixed before the
        product is released for full scale manufacturing and
        distribution.
     
        (2001-04-21)