Module & Components Integration Testing Phase

Module components are integrated and tested as assemblies to validate that
all of the units work well together.

After all units have been tested in isolation and verified working correctly, the next of testing begins: Integration Testing.

Two Possible Processes

  • Two modules integrated and tested
  • Another module added to them and tested
  • Continues until all units are added


  • Units grouped by functional area
  • Tested together as assemblies

Top Down Testing

  • Top layers tested
  • Lower layer integrated and tested
  • Process continues until full integration

Bottom Up Testing

  • Lowest levels validated
  • Higher level component integrated and tested
  • Process continues until full integration

By testing the units in aggregate, it’s easier to identify the source of the issues found.

Defects general found in this phase

  • Inter-process communication
  • Parameter issues
  • Data issues

Testers involved in this phase should have a solid background in integration testing techniques.

QA Mentor’s Application Architecture Inspection Services as well as our Testing Execution On-Demand Service can be used to provide you with that expertise to perform Integration testing either after or independent of unit testing.

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