depending on the project and the software product. For example, there may be component integration testing after
component testing and system integration testing after system testing. Test levels can be combined or reorganized depending on the nature of the project or the system architecture. For the integration of a commercial off-the-shelf (COTS) software product into a system, a purchaser may perform only integration testing at the system level (e.g. integration to the infrastructure and other systems) and at a later stage acceptance testing.