In software testing, three terms are used very regularly – test scripts, test cases and test scenarios. However, in order to apply them efficiently, it's important to understand their differences, and that each term implies a different level of detail and has a distinct purpose.
A test script is the most detailed way to document software testing. It typically has 'steps' in the form of code that should be performed manually. These scripts also include expected results for each step, for example, 'Click the Apply button', with an example result of 'A form opens'. Test scripts are written in programming languages, such as Java, Python, Ruby, and are short programs used to test discrete parts of the software system. In other words, test scripts are automated sets of steps that have to be executed by the tester.
A few things should be considered before going all-in with test scripts. Software projects change often; pages get redesigned and user navigation also changes. This is the reason test management software should be used to update the scripts to match the new versions. Using testing software saves time and is also cost effective in the longer run.
Secondly, by using testing software, scripts can be made more versatile by testing the same condition using different steps and different data. To achieve this, however, testers need to be more intuitive and creative when writing scripts.
A test case is a documented set of preconditions (prerequisites), procedures (inputs/actions) and postconditions (expected results) which a tester uses to determine whether a system under test satisfies requirements or works correctly. Test cases have a great impact on the testing phase. Writing test cases is almost as important as the testing process itself. The activity of writing test cases helps you think through the details and ensures you're approaching the tests from as many angles as possible. The long-term value of having test cases is that anyone can go in and retest using the test case. Test cases are powerful artefacts that are also beneficial for future teammates, as well as a good source of knowing how a system and particular feature works.
Test scenario is the least detailed and high-level type of documentation. A test scenario is a description of an objective a user might face when using the program. They cover an end-to-end functionality which is to be tested. An example might be 'Test that the user can successfully log out by closing the program.' So, this scenario will require testing in a few different ways to ensure the scenario has been entirely covered.
Test cases are derived from test scenarios, whereas test scenarios are derived from test artefacts such as Software Requirement Specification (SRS) and Business Requirement Specification (BRS) documents. Test scenarios ensure that the business processes and flows are as per the functional requirements. They also serve as a quick tool to determine the most critical end-to-end transactions or the real use of the application.
How to Choose?
The most comprehensive process uses all three in tandem to tune the testing to varying skill levels and domain knowledge across a group.
If the software has a task which needs to be repeated regularly, test management tools such as Testworthy can be used to create accurate and repeatable automated test scripts across multiple devices, platforms, and environments easily and quickly. On the other hand, test cases are ideal when there are a number of ideas and skilled testers onboard to determine the best way to test them. Lastly, test scenarios are best suited when there is a new workflow and there is a need to think broadly about the actions that may be taken by users. In a nutshell, all of these forms of documentation provide value, as long as there is a clear understanding of their benefits and their limitations.