QA testing services are an essential part of success in today's software development environment for building high-quality apps. Every software product must meet high requirements for functionality, performance, and usability, whether it is designed for consumer or enterprise markets. Carefully designed test cases are one of the best ways of achieving this. Defects are less likely to affect customers when software works as expected across various kinds of scenarios because of a reliable test case design base.
Reliable test case design strategies may improve the success rate and coverage of your software testing activities, particularly if you are working with a QA software testing companyor depend on software testing services. We'll look at the necessary test case design strategies in this article, that every tester needs.
Test Case Design Techniques
1. Equivalence Partitioning
It is a fundamental technique that involves dividing input data into partitions or classes, where all the data in each partition is expected to behave similarly. This technique allows you to test one representative value from each partition instead of testing every possible input.
Example:
Imagine testing an input field that accepts age values between 1 and 100. With equivalence partitioning, you could break this range into three partitions:
- Values below 1 (invalid inputs)
- Values between 1 and 100 (valid inputs)
- Values above 100 (invalid inputs)
Testing one value from each partition, such as 0, 50, and 101, would ensure coverage of all relevant scenarios without overburdening the testing process.
Benefits:
- Reduces the number of test cases by grouping similar inputs.
- Ensures broad coverage with minimal test duplication.
- Easy to implement and effective for most input-based systems.
Equivalence partitioning is an effective tool for increasing test efficiency, that is important for quality assurance teams in testing companies to fulfill deadlines and satisfying customers.
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2. Boundary Value Analysis (BVA)
BVA is a technique that focuses on the "boundaries" of input data. Most systems are more likely to fail at the edges of input ranges, so BVA tests these critical points. When applied in combination with equivalence partitioning, it provides an extensive understanding of system behavior at input boundaries.
Example:
Consider a function that accepts values from 1 to 100. BVA would test at the boundaries: 0, 1, 100, and 101. This helps to catch errors that occur when transitioning between valid and invalid input values.
Benefits:
- Highly effective in catching edge-case bugs.
- Minimizes test cases while focusing on critical areas.
- Helps uncover unexpected behaviors at data limits.
In the context of QA testing software, BVA is especially useful for testing numeric inputs, form fields, and input validation logic, ensuring the software reacts appropriately at the edges of its expected input range.
3. Decision Table Testing
This is a structured technique that documents different input combinations and their corresponding system outputs in a tabular format. This method is ideal for testing applications with complex business logic or multiple rules and conditions. The table consists of conditions and actions, where each combination of conditions represents a unique test case.
Example:
In the above example, the
T stands for correct Email id/password.
F stands for incorrect Email id/password
H stands for Home screen to be displayed to the user
E stands for the Error message to be displayed to the user
TC stands for the Test case.
Now let's discuss the actions or output of the above decision table as per the provided inputs (email id and password).
Test Case 1 - The email id and password are both correct. Hence, the user should be directed to Test sigma's Homepage.
Test Case 2 - The email id was correct, but the password was wrong. Hence, an error message should be shown to the user mentioning "Incorrect Password".
Test Case 3 - The email id was wrong, but the password was correct. Hence, an error message should be shown to the user mentioning "Incorrect Email Id".
Test Case 4 - The email id and password both are incorrect. Hence, an error message should be shown to the user mentioning "Incorrect Email Id".
Benefits:
- Provides a clear and systematic approach to testing complex logic.
- Ensures all possible combinations of inputs are tested.
- Easy to understand and document, making it a great communication tool for stakeholders.
Using decision tables in software testing services can help ensure that all logical branches of a system are covered, minimizing the risk of missing important scenarios.
4. State Transition Testing
State Transition Testing is ideal for applications where the system's behavior changes based on its current state. This technique involves designing test cases around state changes and the transitions between states. For example, a user login system could have states like "logged in," "logged out," or "locked out" after multiple failed login attempts.
Example:
Consider a state machine for a traffic light control system. States of "green," "yellow," and "red" are used in combination under the system. State transition testing may ensure that, when responding to the appropriate triggers (such as timer expiration or operator overriding), the traffic light changes state accurately.
Benefits:
- Excellent for testing systems with dynamic state changes.
- Ensures that all valid and invalid state transitions are tested.
- Helps identify unexpected or incorrect state transitions.
For QA testing services, state transition testing is particularly beneficial for applications like workflow systems, mobile apps, or any software that maintains different states based on user input or system events.
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5. Use Case Testing
To verify that the system works exactly as expected when worked with by real end users, use case testing focuses on real-world user scenarios. By using this method, you can be sure that the software matches the requirements of the business and works exactly as expected. Use cases, that describe how users interact with the system to fulfill specific goals, are the source of test cases.
Example:
The use case for an e-commerce website may describe the purchasing process. Every stage of the process, including finding a product, adding it to the basket, checking out, and receiving an order confirmation, would be verified by the test case.
Benefits:
- Tests are user-centric, focusing on real-world usage scenarios.
- Ensures business requirements are met, and processes work as expected.
- Helps improve user satisfaction by validating complete workflows.
QA software testing companies often rely on use case testing to ensure that the software provides the functionality users need and expect, ultimately helping to improve customer satisfaction.
6. Exploratory Testing
With the use of an unknown source but a highly effective approach called exploratory testing, testers can quickly become familiar with the system. Testers understand the product and determine any defects using their imaginations, personal experience, and specific knowledge with the help of pre-written test cases. This method works particularly well when testing new features or when time is important.
Example:
A tester can try to enter unexpected input values, perform unusual workflows, or test edge scenarios that have not been addressed by formal test cases during an exploratory test process. Identifying bugs that might be ignored is the purpose.
Benefits:
- Encourages creativity and domain expertise.
- Helps discover hidden or hard-to-find defects.
- Adaptable and flexible, making it useful in agile environments.
In QA testing services, exploratory testing is often used alongside formal test cases to find defects that structured tests may overlook.
7. Error Guessing
Error guessing is a technique in which professional testers use their knowledge and experience to figure out where errors are likely to be found. However somewhat less calculated than some of the methods explained above, error guessing can be very useful when utilized by trained testers who are knowledgeable about are familiar with software risks.
Example:
A tester familiar with common errors in web forms might specifically test for issues like submitting the form with invalid data, missing mandatory fields, or injecting special characters to see how the system handles it.
Benefits:
- Leverages tester expertise to find hidden issues.
- Often uncovers defects that formal methods miss.
- Complements other testing techniques by filling in gaps.
For teams providing software testing services, error guessing is a valuable technique for finding tricky bugs that may not be covered by standard test cases.
Conclusion
The most important part of any quality assurance process is test case design. Using techniques like Equivalence Partitioning, Boundary Value Analysis, Decision Table Testing, and others confirms that your software matches quality standards without reducing the time and effort required for testing, and this is helpful to testing companies and teams providing QA testing services.
You can make sure that your applications are stable, reliable, and ready to provide an outstanding user experience by including these test case design techniques in your testing plan. These methods will help you in achieving higher standards of software quality no matter whether you're making use of QA testing software or using external software testing services.
About Author
Set the baby steps in 2019 as a trainee in manual testing, Shubham Pardhe has now become an experienced QA executive in Pixel QA.
His professional goal is to become an expert in test management tools.