How to Perform Integration Testing

Integration testing is a level of software testing process where individual units are combined and tested as a group. Integrating testing is performed to find out defects in the interface and between integrated components. Integration testing is performed by independent testers or it can be performed by developers of software testing companies. Integration testing is very important for software testing and consists of four steps.

• Acceptance testing
• System testing
• Integration testing
• Unit testing

Classification of Unit Interfaces:

The developer of each program unit ascertains and documents the unit’s interfaces for the following unit operations:
Here is a list of test cases for integration testing.
• Exte
al inquiry
• Exte
al input
• Exte
al filing
• Exte
al display
• Exte
al output

In exte
al inquiry it has to be observed whether the queries from terminals for information are getting right response.

Exte
al Input:

In this step all the entered data is tested whether the data entered for processing is managed properly or not.
Exte
al Filing:

At this level it is tested that all files are updated and all transactions are creating files properly on computer.
Internal Filing:

At this level it is to be checked that all receiving and passing information from other logical processing units are correct or not.

Exte
al Display:

It is to observe that the system is correctly processing sending message to terminals.

Exte
al output:

It is to check that the result of processing is being received by some output device or unit.
Reconcile Interfaces:

This information is required for the integration test template. That is collected from all program units for software testing.

Creating Integration Test Conditions:

Test condition are created, after the creation of these test condition, test condition is documented on test template for software testing.

Evaluation of Test Conditions:

A list of question is created that will help in the evaluation of test conditions on the integration testing template. This list indicates that test conditions created for the integration process are complete.

• Record test?
• File test?
• Search test?
• -Match/merge test?
• Attributes test?
• Stress test?
• Control test?

So integration testing is performed after unit testing and before system testing. Here are four approaches used for integration testing.

• Big bang
• Top down
• Bottom up
• Sandwich/ hybrid

Big bang approach is one where all units are combined together at tested at once. In top down approach all top level units are tested. In bottom up approach of integration testing, bottom level units are tested before and top level units are tested after that. Sandwich approach is a mix approach of top down and bottom approaches for software testing.

This is how integration testing takes place all of the test cases and approaches plays a very critical role in integration testing. In integrating testing main objective is to define test cases and to apply them using various approaches. In software testing company integration testing is considered an integral part of software testing.