There are various levels of testing i.e. Unit Testing, Integration Testing, System Testing. Each level of testing builds on the previous level.

Unit testing” focuses on testing a unit of the code. 

“Integration testing”  is the next level of testing. This ‘level of testing’ focuses on testing the integration of “units of code” or components.

System Testing focus on the testing the system as  a whole.

Once unit tested components are delivered to integrate them together. These “integrated” components are tested to weed out errors and bugs caused due to the integration. This is a very important step in the Software Development Life Cycle. It is possible that different programmers developed different components. A lot of bugs emerge during the integration step. In most cases a dedicated testing team focuses on Integration Testing.

Before we begin Integration Testing it is important that all the components have been successfully unit tested. 

Integration Testing typically involves the following Steps:

1.       Create a Test Plan

2.       Create Test Cases and Test Data

3.       If applicable create scripts to run test cases

4.       Once the components have been integrated execute the test cases

5.       Fix the bugs if any and re test the code

6.       Repeat the test cycle until the components have been successfully


Test Plan is to plan the testing process in advance for all the aspects, ie. Resources, Deliverable dates, System  Requirements, risk analysis, etc.

A Test Case describes exactly how the test should be carried out. The Integration test cases specifically focus on the flow of data/information/control from one component to the other. 

A Sample Test Case Format:


Test Case ID Test Case Description Input Data Expected Result Actual Result Pass/Fail Remarks

A Lot of errors occur because the wrong version of components were sent
for the build or there are missing components. If possible write a script to integrate and deploy the components this helps reduce manual errors.

Document the Integration process/build process to help eliminate the errors of omission or oversight. It is possible that the person responsible for integrating the components forgets to run a required script and the Integration Testing will not yield correct results.

Integration Testing will lose its edge if the defects are not tracked correctly. Each defect should be documented and tracked. Information should be captured as to how the defect was fixed. This is valuable information. It can help in future integration and deployment processes.

Integration testing is the most crucial steps in Software Development Life Cycle. Different components are integrated together and tested. This can be a daunting task in enterprise applications where diverse teams build different modules and components. In this article you learned the steps needed to perform Integration Testing.


  Modified On Nov-30-2017 12:31:40 AM
  1. Thanks for sharing informative post.

    Your words increase my knowledge for sure. Thanks

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