The process of ensuring that a software system and its associated documentation are in all respects of sufficient quality for their purpose. While a quality assurance team may be involved in all stages of a development project, there is typically a recognized quality assurance activity following completion of development and prior to release of the system for operational use.

The checks performed by the quality assurance team (which should be independent of the development team) vary between organizations and also depend on the nature and purpose of the software system. However they typically include functional testing of the software, checks that programming standards have been respected, that the program documentation is complete and of an adequate standard, and that the user documentation for the system is of the desired quality. The team would also probably explore the reliability of the software system, and attempt to ensure that the software system and its associated documentation are so organized as to promote system maintainability.