Backward Compatibility Testing

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Software testing is one of the most critical steps done to ensure its quality. It is a part of software development lifecycle (SDLC) and performed from its initial phases.

What is Backward Compatibility Testing?

The backward compatibility testing is done to test if new modifications in the software continue to be compatible with its older versions. It guarantees that the end users can move to the latest version of the software without any hiccups.

At the time of backward compatibility testing, the testers examine the multiple features of the software namely data migration, working of APIs, GUI, features, security, and other parameters. Thus it ensures that the end users can leave behind using the older versions and begin using the latest ones without encountering data related or any other issues.

Why is Backward Compatibility Testing Done?

The backward compatibility is an exhaustive testing technique done to ensure that the users can shift to the newer versions of the software uninterrupted. It fetches good customer feedback on the software and minimizes the chances of data disappearance post an upgrade.

The backward compatibility testing increases customer confidence, loyalty, and trust on the software and minimizes the need for customer support assistance after updates. Thus it helps to save a lot of cost.

How to Perform Backward Compatibility Testing?

The backward compatibility testing can be performed both manually and by automation. In the manual process, the testers execute defined steps to test the compatibility. For example, a tester creates a complicated excel sheet to track various aspects of the project using the excel 2000 version. Then he upgraded the excel version to 2010. After that, he verifies if all the features he had been using in the older version of the excel is still working in the latest version of the excel.

The backward compatibility testing through automation is performed by executing test scripts or using any automated tools to make the process of testing the compatibility to the latest version easier. For example, the automated tests created for older versions of software are again run on its latest version and the results are analyzed.

What is Backward Compatibility Testing Composed of?

The backward compatibility testing is mainly done to check if the latest version of the software is compatible and it has no data loss or GUI issues. For example, while the latest version of an e-commerce application is released, at first all its functionalities which are to be carried forward from the older versions are verified.

What is Tested in Backward Compatibility Testing?

The backward compatibility testing is done to validate the items listed below −

Data Compatibility

This is done to test if the data prevailing in the older version of the software can be used in its newer version without any issues. For example, Excel was created in version 2000. The data compatibility ensures that once the excel application has been upgraded to its latest version, we can continue accessing the same data created in its older versions.

Functional Compatibility

This is done to test if all the functionalities of the software developed for its older versions, continue to work seamlessly once it has been upgraded. For example, while the latest version of an e-commerce application is released, all its functionalities in the older version will continue working in its latest version as well.

Interface Compatibility

This is done to test if the user interfaces like buttons, links, menu, tabs, etc are working properly once the software is upgraded. For example, as the operating system of an iphone has been upgraded, the user interfaces should have the same appearances, functionalities and they are compatible with latest versions of the operating system.

Configuration Compatibility

This is done to test if the latest version of the software looks perfect and is working as expected in different devices, setups etc like phones, tablets, desktops. For example, while the latest version of an e-commerce application is released, it should be accessible in various browsers, smartphones, tablets, desktops etc.

Advantages of Backward Compatibility Testing

The advantages of backward compatibility testing are listed below −

• It allows the users to utilize the data and processes created for the older versions of the software in its latest version as well. For example, the data and apps in the phone remain intact even after its update.
• It enables the usage of the various versions of the software and hardware. For example, the older websites can be accessed in the latest version of the browsers.
• It helps in product marketing and gives the user a feeling of being valued and trusted.
• It helps to add new products that work with older versions of the software. For example, a new car accessory is compatible with previous versions of the car infotainment system. This allows the customer to use it without the need to get a new car infotainment device.
• It allows the updates to the software without impacting the existing users. For example, an e-commerce application gets updated frequently, but that does not result in data loss or any issues for the ongoing customers.

Process of Backward Compatibility Testing

The processes of backward compatibility testing are listed below −

Step 1 − The first step is to determine what all the features of the older versions of the software will be carried forward in its latest version.

Step 2 − The second step is to define the test objectives and scopes.

Step 3 − The third step is to identify the test environment to carry out the backward compatibility testing.

Step 4 − The fourth step is to identify and generate the relevant test data.

Step 5 − The fifth step is to design the test cases for the backward compatibility testing.

Step 6 − The sixth step is to run the designed test cases and examine its results.

Step 7 − The seventh step is to identify the deviations in the expected and actual results, and report the bugs.

Step 8 − The eighth step is to prioritize the bugs encountered while running the compatibility tests. For example, the bug created for the issue where a new software version crashes in the older devices should be fixed as soon as possible.

Best Practices to Design a Backward Compatibility Test Case

The best practices to design a backward compatibility test case are listed below −

• Verify all the old features of the software are working correctly in its latest version.
• Prioritize the compatibility bugs and work with the developers to understand the new changes in the software.
• It should ensure good test coverage.
• Simulate actual user actions to cover real life scenarios and use cases.
• Use automation to complete the compatibility tests.
• Verify in multiple environments, hardware and software.

Conclusion

This concludes our comprehensive take on the tutorial on Software Backward Compatibility Testing. We’ve started with describing what is backward compatibility testing, why backward compatibility testing is done, how to perform backward compatibility testing, what is backward compatibility testing comprise of, what are tested in backward compatibility testing, advantages of backward compatibility testing, what is the process of backward compatibility testing, and what are the best practices to design a backward compatibility test case. This equips you with in-depth knowledge of Software Backward Compatibility Testing. It is wise to keep practicing what you’ve learned and exploring others relevant to Software Testing to deepen your understanding and expand your horizons.