What is need of Integration Testing?

Answer

Although each software module is unit tested, defects still exist for various reasons like

• A Module in general is designed by an individual software developer whose understanding and programming logic may differ from other programmers. Integration testing becomes necessary to verify the software modules work in unity
• At the time of module development, there are wide chances of change in requirements by the clients. These new requirements may not be unit tested and hence integration testing becomes necessary.
• Interfaces of the software modules with the database could be erroneous
• External Hardware interfaces, if any, could be erroneous
• Inadequate exception handling could cause issues.