Test Case vs. Test Scenario: What’s the Difference?

Like the good old riddle about which comes first, the chicken or the egg, we can draw a similar parallel to two crucial terms in software testing—test case and test scenario. Which comes first? In this blog post, we will explore both terms and share the main differences between the two. Let’s start with a brief lesson on test cases.

What is a test case?

A test case can be described as a set of instructions that need to be followed and executed in order to test a specific feature or functionality of a software application. It covers various different situations, like user login, transactions, registration, forgotten password, button interactions, and many more. Test case documents generally include information about test steps, test data, preconditions and postconditions, making sure that the test case can be carried out as precisely as possible. Test cases are usually written by quality assurance engineers or testing teams to ensure that they are properly crafted, easy to understand, and can be executed correctly.

Types of test cases

There are various types of test cases:

• Functional test cases. These test cases are developed to test the user interface functionality of the software application and make sure that it achieves expected results. This type of testing is considered black box testing, as tasks can be executed without having access to the internal structure or software code, and is based solely on requirements.
• Performance test cases. These types of test cases are designed to assess the responsiveness and effectiveness of a system after user interactions or while on standby. Performance test cases can include various complex measurements that check whether the software performs well and is as good or better than alternative solutions. Tests should also evaluate how the system works under different conditions, such as internet speeds, user loads, signal strengths, and more.
• Usability test cases. Usability test cases are created to test the application as a whole rather than separate parts of it. Testers are given a high-level scenario to execute, which allows them to evaluate how easy and manageable the functions of the system are and whether the user can get full control over all the necessary features. These test cases are usually written by testing and design teams and do not require any inside knowledge of the system, as the key evaluation criterion of this type of test case is how user-friendly and intuitive the app is.
• Database test cases. These test cases are designed to test the backend architecture of an application and determine whether the data is stored, acquired and maintained according to set standards. Testers should have internal and in-depth knowledge about the application and database to successfully perform actions related to database test cases. As data security is very important, these test cases should be carried out with great attention to detail.
• Security test cases. Security test cases are used to verify that an application is safe to use and that user data can not be stolen or manipulated during and after the use of the application. These test cases focus on transactions, permissions and encryption, as well as assessing the application’s resilience against penetration attempts, breaches and system hacks that aim to exploit or acquire valuable user data. They are generally written by security teams within the organization.
• Integration test cases. These test cases aim to identify how different software modules or parts work together when integrated to achieve the expected result. In addition, testers may need some insight from developers to precisely write and execute test cases.
• User interface test cases. User interface test cases are needed to validate the visual aspects of an application and its elements. Namely, whether they work and display as expected, and whether there are any spelling or grammatical errors. A crucial part of user interface testing is to check cross-browser functionality and make sure that the product works as intended on different browsers as well. These test cases are created by the quality assurance team, but the design team helps out with the writing.
• Regression tests. These tests reveal any problems or discrepancies in the system that may occur due to recent code changes or additions. Testers can decide whether to rerun all of the test cases or only the most important ones, as code changes can happen frequently and, realistically, executing every test case is not possible.

Why are test cases important?

Test cases are very important in software testing because they can provide a wide coverage of the system, giving clients a clear understanding of how their product behaves and where defects are found. This way, they can focus their attention and effort where it is most needed. Test cases can be used to track test coverage, making sure that all of the existing features and software requirement specifications are covered. Overall, test cases make the testing process much more organized, efficient and thorough, as every detail and feature is investigated, documented and reported to the client.

Tips for creating an effective test case

1. Make sure the test case is straightforward. A test case should be clear and concise, with all of the necessary information in one place. Using short and precise sentences will save a lot of time and effort when executing the actions.
2. Think like an end-user. The purpose of a test case is to make sure that the software works as intended for customers. During the test case writing process, imagine yourself as the end-user and identify the most important actions and flows in the application. After doing so, incorporate them into the test case and validate them.
3. Name the test case. Provide identification information, like a number, to the test case so that it can be tracked and easily found at any time. The test case ID must be unique.
4. Include all necessary data. Before finishing the test case, make sure that it includes essential details, like test environment, test data, unique identifier, expected and actual results, pre and post-test actions, as well as a brief description of what is being tested and what methodology is being used.
5. Make the test case reusable. Create the test case in a way that it is reusable and independent from other test cases. This will allow you to execute it as a separate test, without relying on other requirements to succeed.
6. Set test priorities. Decide which actions and flows within the application are the most important and need to be tested first.
7. Follow the specification document. Do not make assumptions about system behavior or potential occurrences. Instead, focus on what is written in the specification documents—expected results and any assumptions.
8. Write unique cases. Check your test cases regularly to avoid creating duplicates.
9. Ensure test cases are reproducible. Make sure that the test case produces consistent results every time, no matter how many times it is tested and by whom.

Test case example

Let’s take a look at an example of a test case for a login page.

What is a test scenario?

A test scenario is essentially a high-level idea of an action that needs to be tested within an application or system. You can think of a test scenario as any real-world scenario where software can be used to achieve a certain goal, for example, buying a train ticket through a mobile application. A test scenario consists of multiple test cases with detailed instructions about how to test specific end-to-end functionality and user experience. Test scenarios are usually created in collaboration with stakeholders, developers and end-users to ensure comprehensive coverage of critical flows and actions.

Why are test scenarios important?

Test scenarios ensure extensive coverage and thorough investigation of all the possible use cases in the project, as many parties with different specifications are involved in creating them. This makes sure that every detail and process is tested within the software. Another reason test scenarios are important is that they help with resource planning. Specifically, workforce, budget, and the time needed can be estimated by looking at some of the test scenarios and checking how many use cases are covered. Additionally, test scenarios help to identify the main purpose of the software and cover the most important end-to-end functionalities.

Tips for creating an effective test scenario

• Think from an end-user perspective. Just like when writing test cases, it is crucial to write meaningful and successful test scenarios from a user's point of view.
• Write one test scenario per user scenario. To avoid confusion and clutter, create one test scenario for each user story or requirement.
• Prioritize scenarios. In complex projects, not every scenario can be executed. Therefore, select which scenarios are most important for your users.
• Ensure test scenarios are reusable, reproducible, and specific. Make sure test scenarios cover specific user stories in detail, can be tested independently, and include key information.

Test scenario example

Here are some of the most common test scenarios that serve as a foundation for deriving test cases.

• Test Scenario 1: Test the login functionality
• Test Scenario 2: Test the forgot password functionality
• Test Scenario 3: Create a new account
• Test Scenario 4: Check the payment functionality

Major differences between a test case and test scenario

When it comes to software testing, both test cases and test scenarios play a significant role in the testing process. However, as we can see above, they differ in terms of scope, level of detail, and purpose. Let's explore the main differences between test cases and test scenarios.

• Focus. Test cases generally focus on how to test—outlining the steps and procedures. Test scenarios, on the other hand, focus on what to test—determining which aspects of the software to test.
• Scope. Test scenarios are designed to define end-to-end functions to be tested, whereas test cases provide instructions on how to test specific features, functions, or appearance in greater detail.
• Origin. Test cases are derived from test scenarios, while scenarios are based on different documentations, including user stories and requirements.
• Level. Test scenarios are high-level actions,while test cases are low-level actions.
• Result. Test cases bring structure to the whole testing process, while test scenarios are broader definitions of a testing subject.

Conclusion

In the end we got the answer to our question—what comes first, the test case or the test scenario?  The answer is the test scenario. The test scenario comes first, and then test cases are extracted from the scenario. But regardless of which comes first, the important thing to remember is that both test scenarios and test cases play a crucial role in the software testing process to ensure a successful software release.

We hope that this blog post has provided you with valuable insights into test cases and test scenarios—the different types, why they are important, how to write them effectively, and what the main differences between the two are.

Be sure to follow our tips when creating your test cases and test scenarios to ensure you achieve accurate and reliable results.

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