Integration test must be planned. Planning can begin when high-level design is complete so that the system architecture is defined. Other documents relevant to integration test planning are the requirements document, the user manual, and usage scenarios. These documents contain
structure charts, state charts, data dictionaries, cross-reference tables,
module interface descriptions, data flow descriptions, messages and event
descriptions, all necessary to plan integration tests. The strategy for integration should be defined. For procedural-oriented system the order of
integration of the units of the units should be defined. This depends on
the strategy selected. Consider the fact that the testing objectives are to
assemble components into subsystems and to demonstrate that the subsystem functions properly with the integration test cases.