• Tests on components or complete system, combining units
that have already been thoroughly tested
• Emphasis is on integration and interfaces
• Uses trial data that is typical of the actual data, and/or stresses
the boundaries of the system, e.g., failures, restart
• Is carried out systematically, adding components until the
entire system is assembled
• Open or closed box: by development team or by special
testers
System testing is finished fastest if each component is
completely debugged before assembling the next