Unit test implemented early in the iteration.focuses on verifying the smallest testable elements of the software.Unit testing in typicall applied to components in the implementation model to verify that control flows and data flows are covered and function as expected.These expecttions are based on how the component participates in executing use case.whict you find from sequence diagrams for that use case.The Implementer performs unit test as the unit is develaped. The details of unit test are described in the implementation workflow.
Integration testing is performed to ensure that the components in the implementation model operate properly when combined to execute a use case .The targer-of-test is a paokage ora set of packages in the implementation model.Often the packages being combined come from different development organizations.In tegration testing expose in completen ess on mistakes in the packages interfacespecifications.

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