Regional Regression Testing (RRT)

Testing the changes and impact regions is called Regional Regression Testing. 

The module 1,2,3,4 is given by developers for testing during the 1^st build. The TE finds a defect in Module 4. The defect report is sent to the developers and the development team fixes the bug and sends the 2^nd build in which the bug is fixed. Now, the TE realizes that defect fixing in module 4 has impacted some features in module 1 and 3. So, the TE first tests module 4 where the bug has been fixed and then tests the impact areas i.e, module 1 and module 3. This is known as regional regression testing. 

for ex:

After the 1^st build, the customer sends some changes in requirement and also to add new features to be added to the product. The requirements are sent to both development team and testing team.

The development team starts making the changes and also building the new features as per the requirements.

Now, the test lead sends a mail to the customer asking – which and all are the impact areas that will be affected after the necessary changes are made – so that he will get an idea as to which and all features needed to be tested again. He also sends a mail to the development team to know which and all areas in the application will be affected as a result of the modifications and additions of features. And similarly he sends a mail to his testing team for a list of impact areas. Thus he gathers impact list from the customer, development team and also the testing team.

This impact list is sent to the all testing engineers who look at the list and check if their features are modified and if yes they then they do regional regression testing. The impact areas and changed areas are all tested by the respective engineers for whom the features are allotted. Each TE tests only his features which could have been affected as a result of the changes and modifications.

The problem with the above method is that the test lead may not get the full idea of the impact areas because the customer and development team may not have so much time to respond to his emails.