Integration Testing And Its Approaches

Integration Testing And Its Approaches 

What is Integration Testing:

• Testing is conduct by integrating two or more component 
• with in the same system or two different system are integrated.
• It is a phase in software testing in which individual software modules are combined and tested as a group.
• During the integration we verify the data communication    between the component.
• We calculate the performance.(Time taken to complete the transaction)
• We verify the function of the application.

Integration Testing Approaches:

• Big - Bang Integration approach
• Incremental Approach

1. Top - Down Integration
2. Bottom – Up Integration
3. Mixed Or Sandwich integration 

1. Big – Bang Integration Approach

• Testing is conducted on multiple component together.
• All the units are tested together as one single combined unit.
• This form of integration testing works well for smaller systems.

Limitations Faced in Big – Bang Integration Approach

• In this approach Detailed testing is not possible if any defect is found it will take time or effort to analysis the defect. 
• It is also difficult to find the root cause of a defect in this method.
• Critical modules are not prioritized which could increase the overall risk.

2. Incremental Approach

• In Incremental integration testing, the developers integrate the modules one by one using stubs or drivers to uncover the defects. This approach is known as incremental integration testing.
•  Testing, in which components or systems are integrated and tested as long as all components or systems are integrated and tested completely.

Types of incremental  approach

• Top - Down Integration:- Testing is conduct from main module to sub module. In this approach verify the data updated in main module is updated in sub module.  
• Bottom – Up Integration:- Testing is conduct from sub module verify the data tested in sub module thus make sure that highest module is tested properly.
• Mixed Or Sandwich integration:- It is combination of top-down and bottom-up integration. 

Stubs And Drivers

This are the temporary component which are used in place of sub module and main module 

Stubs :-  It is substitute for sub module in top - down integration approach.

Driver :- It is substitute for Main module in Bottom - up  integration approach.

Advantages of Integration Testing 

•  It ensures that internal modules and components communicate properly.
•  It performs regression testing on important connection points.
•  It also helps to detect the issues related to the interface between modules.
•  Integration testing helps to stimulate the interaction between various modules.
•  It Covers multiple modules to provide broader test coverage.

Disadvantages of Integration Testing 

• Difficult to perform – It is very difficult to perform as compared 
• to system testing in which we can consider the application as a 
• black box.
• Time-consuming – It is very time-consuming and 
• resource-intensive to test all the interfacing between the different connected modules.
• Additional efforts – It requires the creation of stubs and drivers which if not created correctly can result in inadequate testing.

Please refer below video for more detail on Integration Testing And Its Approaches: