Discuss in details about Integration testing.

• It is a systematic procedure to construct the program structure.
• Incremental integration - The program is built and tested in small increments.

Top-down integration

• It is an incremental method.
• Modules are integrated by moving downward through the control hierarchy starting with the chief control module(main program).
• Subordinate parts are incorporated by depth-first or breadth-first way.

Bottom-up integration

• This testing starts construction and testing with the elements at the lowest levels in the program structure.

Regression testing

• It is the re-execution of some subset of tests that have previously been conducted to make certain the changes that have not been propagated unintended side effects.

Smoke testing

• It reduces the integration risk.
• Error analysis and correction are simplified.