Software Testing - Levels

The software testing is the one of important processes followed in the software development life cycle to ensure that the product or the application under test is delivered as per quality standards. This means that maximum bugs or the defects in the application should be detected, and resolved and it should work seamlessly with the customers. In order to achieve this, the software testing goes through various levels of testing.

Different Software Testing Levels

The different types of software testing levels are listed below −

Unit Testing

This is first level testing done by the developers before handling the application to the testing team to ensure that the individual units of the application are working as expected. This type of testing is done to segregate small, individual units of the product and check if they are developed as per the requirements.

Thus unit testing is done to catch bugs at the early stages of software development life cycle. It identifies the regression defects as well. The effort and cost of doing unit testing is not much, and it helps to confirm if the code developed is working properly.

However, in most situations, it is seen that the unit test fails to detect bugs or defects in the application. Also, it eats up the developers time to design unit test cases.

Integration Testing

This is the second level of testing conducted by the testers to verify if multiple unit tested modules are working together collectively without any defects seen at the integration or at interface of the modules. The integration testing can be done either manually or by automation. The integration testing helps to increase the test coverage and identifies the defects or bugs that come up while multiple units are combined. The defects detected at this level are easier to fix, than later stages.

The time, effort, and resources to carry out integration testing among modules is higher. The integration testing requires creation of drivers, and stubs correctly else, it will produce incorrect results.

System Testing

This is the third level of testing where the entire product comprising all the modules, and sub-modules is tested to ensure that all the requirements are fulfilled, and the product is working properly in its working environment without errors. It is the third level of testing and covers the end to end flow of testing.

The system testing verifies if the product is working as per the software and business requirements. This is a critical level of testing to prevent defect leakage at the production. The system testing involves consumption of huge time, effort, and resources to complete testing.

Acceptance Testing

This is the fourth and final level of testing done to verify if the product or the application under test is built correctly as per the user requirement and fit to be shipped to production. It is done to catch both cosmetic as well as functional defects in the product. The acceptance testing ensures that the product is working as expected in the customer’s environment and it finds bugs or issues just before the product is released to its actual users.

In the acceptance testing, sometimes the product is also tested by the customers themselves, and thus helps in building the customer's confidence, and faith in the product. The customers get an idea, and data on how the product will behave with respect to some real life scenarios. Since the acceptance testing is the final level of software testing, it requires a lot of planning, and resources. Any test case can be picked and chosen for acceptance testing by the customers.

Conclusion

This concludes our comprehensive take on the tutorial on Software Testing - Levels. We’ve started with describing what the different software testing levels are. This equips you with in-depth knowledge of Software Testing - Levels. 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.