Test Case vs. Test Scenario: Differences, Types, and Best Practices
In software testing lifecycle, you’d come across two of the most common terms: test cases and test scenarios. After all, these are the building blocks of testing. Getting them right is critical to product success.
Test scenarios are derived from a use case, whereas a test case is derived from a test scenario. Using both, we ensure software quality and robustness. Bit tricky, right?
Well, to simplify, we are going to discuss the differences between a test case and a test scenario, their types, examples, best practices, etc. Let’s begin.
Table Of Contents
- 1 What is a Test Case?
- 2 What is a Test Scenario?
- 3 Key Differences Between Test Case and Test Scenario
- 4 Wrapping Up
- 5 Frequently Asked Questions
What is a Test Case?
A test case is where test execution begins. It is a document that comprises the set of conditions required to verify if an application is working as expected. These conditions range from preconditions, case name, specific user steps, input values, expected result, actual result (after test completion), software status (before & after tests), and final remarks.
Every test intends to check if the app/site matches the expected result, as outlined in the test case. Thus, the test case defines how to actually set up and run the test, as well as what the ideal result should be.
Test cases are built off pre-constructed test scenarios, and define the specific protocols to verify compliance against particular requirements.
What are the situations that can be tested?
Test cases are required to test every possible functionality, performance level and design element that the software under test intends to provide to end users. These situations differ widely, depending on the software’s target user base as well as the industry it serves. If an end-user can do it, it needs to be tested – signup, purchases, transactions, social sharing, logout, data storage, and infinite other use cases.
Additionally, the app’s in-built offerings around security, speed, and flexibility under different conditions must also be tested, requiring test cases to be defined for each circumstance. For example, how does the app/site work when subjected to weak internet? Does it render appealingly on all screen sizes?
Essentially, test cases must ideally be defined to eliminate as many technical or business flaws as possible before software hits prod. It does this by defining test circumstances for every possible (or as many as possible) real-world usage situations.
Types of test cases
- Functional Test Cases: These define tests to check if an app’s UI works in tandem with its backend systems to do everything it is meant to. These are black-box tests that don’t require knowledge of internal technical mechanisms. The one question to be answered is: If the user does this, how does the app respond?
These tests can be performed in each sprint as soon as a function is developed. Such test cases can be written before the actual code is generated based on precise requirements.
- UI Test Cases: These define tests to check that each UI element looks and works as intended. The tests also verify aesthetic elements – appearance, spelling and grammar, as well as functional ones – misdirects, broken links, etc.
Often, these test cases are built with contributions from design teams. Verifying cross browser compatibility also falls under the ambit of UI test cases.
- Performance Test Cases: These are meant to validate a site/app’s loading speed and accuracy of response. The question is: How fast does the software return the appropriate response to a user action?
Performance test cases must also define tests to check if software is functioning at optimal levels even when it is being accessed by a large number of users, i.e. load testing, spike testing, endurance testing, etc.
- Integration Test Cases: These define tests seeking to check how different software modules/components integrate and interact. The question here is: Are the interfaces between different components working together to generate desired results in response to user actions?
- Usability Test Cases: Test cases defined here check the high-level usability of the app rather than verifying specific features. The test steps outline how an end-user would naturally approach and use the app, including common user paths. The question to be answered is: Can an app user utilize every feature the app promises with reasonable ease?
Once again, this requires no understanding of the app’s tech blueprint, as tests need to be conducted from an actual app user’s POV.
- Database Test Cases: These test cases verify the backend functionality that allows the app to work as expected. Once a user requests something by clicking a button/link/menu item/design element at the UI end, how does the app’s architecture work to deliver the expected result in response?
Needless to say, database tests require testers to have in-depth clarity on how the inner mechanisms work. To monitor if data is stored and used consistently and safely, one must be perfectly clear on how data usage and storage actually works.
- Security Test Cases: Tests cases in this category are designed to verify security of user data and transactions while and after using the app. It should also check the app’s resilience against attempts to penetrate, breach, hack and gain unauthorized access to guarded data.
Example of a Test Case
Let’s create a test case around the simple action of a user login to a website. But before writing the test case:
- Obtain a prototype of the login screen to run the test on.
- Obtain the SRS document and functional requirements document for the project.
- With a prototype and requirements documents in hand, start writing the test case.
In the test case, outline steps and conditions to answer the following questions:
- Which control/fields, static or dynamic, are visible to the user for this test? What steps should be taken to ensure that they are working as expected?
- Are the dynamic links (login button and hyperlinks) responding accurately to user interactions?
- Is the UI communicating with the site database accurately? For e.g., once the user enters their username and password, the software has to verify the same with the right backend database and approve/disapprove the login.
- Are all processes associated with the feature working as expected? For e.g., if the user clicks the “Forgot Password?” link, does it automatically send an email to the user’s registered email ID with the reset link?
- Is the basic flow in place? In this case, does the URL path work accurately in all browsers and allow login as long as correct credentials are entered?
- Does the site work as well on mobile browsers as long as the right credentials have been entered?
- What happens when the user logs out? Do they return to the login screen?
- What happens when the user enters the wrong login credentials? Are the accurate error messages being displayed in response?
Why do you need to write test cases?
All software tests begin with a test case. It details exactly what conditions are required and what steps should be taken to verify the accuracy of a system. It also mentioned the input values said system requires to trigger a software function and return the corresponding output.
Creating test cases is also a great way to track test coverage. Once all test cases have been formalized, they should be studied as a whole to verify if tests match all software requirements and existing features. Ad-hoc testing simply does not provide this insight.
Fundamentally, test cases are written to provide structure and comprehensiveness to the software testing process. They keep track of tests designed, tests executed and the pass/fail ratio. They also reveal any untested features, which might cause disruptive user experience if they were to escape into production.
Best Practices for creating Test Cases
- Prioritize simplicity. The test case should be easy to immediately understand and quickly set up for execution. Detail everything required for a single test so that testers do not have to look for information before getting started.
- Put yourself in the end-user’s shoes. The point of each test is to check how well the software works for the end-user. When drafting a test case, understand what your target users want, prefer, and prioritize, and outline the steps to check those accordingly.
- Name test cases in line with an established naming convention. This is also important to maintain traceability according to requirements.
- Include a reasonably detailed description of what is being tested and the test methodology. Include details on the test environment, requisite data and tools.
- Include all assumptions and preconditions for each specific test.
- Mention every single step so that the tester follows the specific user path involving the feature under test.
- As far as possible, make the test case reusable. Try to eliminate dependencies or conflicts that make it interdependent instead of independent.
- Rank test cases by priority so that the high priority features and scenarios are tested first.
- Clearly describe the expected test results and how the software should appear after a certain feature has been triggered (post conditions).
Now, moving on to test scenarios.
What is a Test Scenario?
At a high-level, a test scenario is any real-world scenario in which software is likely to be used. For example, most apps and sites require users to log in and out. Thus, in this case, logging in and out would constitute a test scenario. These scenarios relate to and reflect the software’s real world applications and use cases.
Test scenarios can be both positive and negative. It usually includes multiple test cases seeking to check the end-to-end functionality of a specific feature – the different ways in which actual users utilize a feature. It includes all testable requirements in one place, which are then sub-categorized based on the module and its uses.
Test scenarios are best created by getting inputs from technical and business teams as well as end-users. Since they seek to define how the software will be used after release, they should be built with different, layered perspectives in place.
Example of a Test Scenario
In this case, let’s take the example of the search functionality of eCommerce. The larger test scenario is “Can the user search for products they want and get exactly what they are looking for?”
Deriving from this scenario, multiple test cases can be created to check if every facet of the search function is working as expected. For example, you can craft test cases for:
- Is the search bar visible, visually appealing and placed accurately in the UI? Does it block any other images/buttons/links?
- Does the search bar respond accurately to specific keywords and phrases? Does it return the desired results?
- Do search filters – price range, product rating, product material (such as fabric), source of manufacturing, color, size, warranty, etc. – work as expected?
As depicted, a single test scenario generates three test cases.
Why should you write test scenarios?
Test scenarios essentially detail the real-world uses of a piece of software. Based on these uses, QAs can build test cases for specific features, user paths and backend compatibilities to verify their efficacy. But when it comes down to brass tacks, test scenarios must also be created for the following reasons:
- Test scenarios should be checked and approved by stakeholders from different business and technical interests, as well as a representative section of end-users. This helps cover all possible uses of software at any given moment. The tests based on these scenarios have a greater chance of covering all possible use-cases before the product goes live.
- A few well-structured and detailed test scenarios can help estimate and organize the effort and equipment required for a project. For example, if the scenarios cover five different use cases, the effort/tools/time required will obviously differ from scenarios that cover ten.
- A quick, high-level skimming over test scenarios is a great way to verify that test coverage is adequate. If you know what situations must be tested, you have a closer idea of how many and what tests must be created to cover those situations.
Best Practices for creating Test Scenarios
Most best practices here will actually match the practices that guide test case creation. This is because the intent of both practices is the same – make testing easy, provide clarity and structure, and empathize with the customer’s requirements.
- Prioritize the end-user’s perspective. What is it that the user would be most likely to do when using the software under test? This is the pivotal question, from which every test scenario emerges.
- Devote one test scenario to one user requirement. This simplifies and de-clutters the process.
- If there are too many test scenarios to run through (as occurs with most layered, complex software), rank them on the basis of customers’ priority.
Key Differences Between Test Case and Test Scenario
The major difference between test case and test scenario is that a test case comprises the set of conditions or steps required to verify if your app works as expected, whereas a test scenario documents real-world use cases of your app, which further help generate test cases.
|Test Case||Test Scenario|
|Defines the steps/actions required to verify the efficacy of a feature. Answers the question “How to test?”||Defines the actual function/feature/to be tested. Answers the question: “What to test?”|
|Focuses on testing singular features, functions and design elements as well as backend functions. Essentially created to define tests at a granular level.||Focuses on defining the end-to-end functions to be tested.|
|Extracted and designed based on test scenarios.||Designed based on previously created requirements (SRS, BRS).|
|Details low-level actions.||Details high-level circumstances.|
|Can be reusable since they describe concrete steps. The same steps can be reused to test different functions, depending on the nature of the software.||Hardly ever reusable since it reflects larger features and usage patterns. If a new feature shows up, a new test scenario will have to be designed.|
|Provides structure to testing.||Reduces complexity of figuring out what needs to be tested in the first place.|
An understanding of test cases and test scenarios, both as individual concepts and the differences between them, is essential for QA teams to streamline and structure tests for maximum efficacy. They can start with what to start, narrow it down to specific features to test, and finally define the granular steps required for the actual test execution.
In other words, test scenarios and test cases provide conceptual and practical frameworks for creating and implementing elegant software tests. Well-designed scenarios and cases go a long way in helping both individual QAs and teams speed up test execution while simultaneously improving the quality, insight, and reliability delivered by said tests.
Treat this article as a starting point for exploring the various types and structures of test scenarios and test cases that may apply to your test projects. The specifics will obviously differ based on the targeted use cases, but the overarching principles, detailed in this piece, should give you more than enough insight to get started on the right foot.
Frequently Asked Questions
Who creates the test scenario?
Usually, scenarios are created by testers themselves. However, they are directly derived from business and technical requirements documents, which are, in turn, created by other stakeholders outside QA and development.
It is best practice to include people from different teams (product, sales, customer success, marketing, etc.) when brainstorming on test scenarios. Diverse viewpoints from teams with different priorities are almost always sure to offer new perspectives. This contributes to creating a more comprehensive test suite that covers most obvious and non-obvious end-user circumstances.
Who writes test cases?
Once test scenarios are completed, QAs or QA managers create test cases to outline how those scenarios can be practically tested. If a team does have access to non-technical stakeholders who may also be acquainted with test cases and protocols, you could always solicit their opinion from an outsider’s perspective.
How do you identify a test scenario?
Here’s a rule of thumb: any part of software that can be tested constitutes a test scenario. When creating test scenarios, ask yourself: “How would an actual end-user navigate this app/site?” Every user path that emerges as an answer will be a separate test scenario.
As mentioned above, it is beneficial to get eyes outside the team when devising test scenarios. Someone from sales or customer success teams will have a more real-world-based understanding of how customers often use an app – because they actually talk to customers who use said app. Similarly, product marketers can help testers with information on industry trends, success metrics, common user preferences across locations, etc. All these can go into creating more refined and relevant test scenarios.
What comes first: test case or scenario?
The test scenario comes first. It details what features and user conditions should be tested. Based on this, you can create test cases that describe the steps required to test each module, feature, sub-feature, and user action derived from the test scenario.