Software Testing Techniques with Test Case Design Examples
Thomas Hamilton
⚡ Smart Summary
Software Testing Techniques help design better test cases by reducing execution needs while maximizing coverage, identifying elusive conditions through structured manual methods. These black box approaches, like Boundary Value Analysis and Equivalence Partitioning, prioritize boundaries and partitions for efficient validation. They complement exhaustive testing limitations, drawing from core principles to enhance reliability.
What is a Software Testing Technique?
Software Testing Techniques help you design better test cases. Since exhaustive testing is not possible, Manual Testing Techniques help reduce the number of test cases to be executed while increasing test coverage. They help identify test conditions that are otherwise difficult to recognize. Software Testing techniques can be classified into the following types:
- Boundary Value Analysis
- Equivalence Class Partitioning
- Decision Table Based Testing
- State Transition
- Error Guessing
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The 7 Principles of Software Testing Techniques
Software Testing Techniques follow a set of principles to conduct the testing process. These 7 principles guide testers to plan, design, and execute tests effectively. These principles ensure that testing remains purposeful, efficient, and aligned with project goals.
The 7 principles of Software Testing Techniques are Testing Shows the Presence of Defects, Exhaustive Testing is Impossible, Early Testing Saves Time and Cost, Defect Clustering, Pesticide Paradox, Testing is Context-Dependent, and Absence-of-Errors Fallacy. You can click on the following link to learn more.
How is AI Transforming Traditional Software Testing Techniques?
AI is revolutionizing software testing by introducing automation, prediction, and adaptability. It enables automated test case generation from natural language using LLMs, self-healing scripts that adapt to UI changes, and predictive defect analysis based on historical data. AI also supports risk-based prioritization, visual testing, and autonomous test execution within CI/CD pipelines. Through natural language interfaces, testers can create cases conversationally, accelerating workflows. In essence, AI makes testing smarter, faster, and more resilient, reducing manual effort while improving accuracy and coverage across modern, evolving applications.
Software Testing Techniques
Boundary Value Analysis (BVA)
Boundary value analysis is based on testing at the boundaries between partitions. It includes maximum, minimum, inside or outside boundaries, typical values, and error values.
Empirical evidence shows that many defects occur near boundary conditions rather than mid-range values. It is also known as BVA and gives a selection of test cases that exercise bounding values.
This black-box testing technique complements Equivalence Partitioning by focusing on the edge cases of the same input ranges. This software testing technique is based on the principle that if a system works correctly for boundary values, it is likely to work for all values within the range.
Guidelines for Boundary Value Analysis
- If an input condition is restricted between values x and y, then the test cases should be designed with values x and y, as well as values that are above and below x and y.
- If an input condition is a large number of values, the test case should be developed to exercise the minimum and maximum values. Here, values above and below the minimum and maximum values are also tested.
- Apply guidelines 1 and 2 to output conditions. It gives an output that reflects the minimum and the maximum values expected. It also tests the values below or above the values.
Example:
Input condition is valid between 1 to 10 Boundary values 0,1,2 and 9,10,11
Equivalence Class Partitioning
Equivalence Class Partitioning divides the set of input conditions into groups expected to produce similar behavior. This software testing method divides the input domain of a program into classes of data from which test cases should be designed.
The concept behind this Test Case Design Technique is that a test case of a representative value of each class is equal to a test of any other value of the same class. It allows you to identify valid as well as invalid equivalence classes.
Example:
Input conditions are valid between
1 to 10 and 20 to 30
Hence, there are five equivalence classes
--- to 0 (invalid) 1 to 10 (valid) 11 to 19 (invalid) 20 to 30 (valid) 31 to --- (invalid)
You select values from each class, i.e.,
-2, 3, 15, 25, 45
Also read more about – Boundary Value Analysis and Equivalence Partitioning Testing
Decision Table Based Testing
A decision table is also known as a Cause-Effect table. This software testing technique is used for functions that respond to a combination of inputs or events. For instance, in a form validation scenario, a ‘Submit’ button activates only after all mandatory fields are completed.
The first task is to identify functionalities where the output depends on a combination of inputs. If there is a large input set of combinations, then divide it into smaller subsets, which are helpful for managing a decision table.
For every function, you need to create a table and list down all types of combinations of inputs and their respective outputs. This helps to identify a condition that is overlooked by the tester.
The following are the steps to create a decision table:
- Enlist the inputs in rows
- Enter all the rules in the column
- Fill the table with the different combinations of inputs
- In the last row, note down the output against the input combination.
Example: A submit button in a contact form is enabled only when all the inputs are entered by the end user.
State Transition
In the State Transition technique, changes in input conditions change the state of the Application Under Test (AUT). This testing technique allows the tester to test the behavior of an AUT. The tester can perform this action by entering various input conditions in a sequence. In the State transition technique, the testing team provides positive as well as negative input test values for evaluating the system behavior.
Guideline for State Transition:
- State transition should be used when a testing team is testing the application for a limited set of input values.
- The Test Case Design Technique should be used when the testing team wants to test a sequence of events that happen in the application under test.
Example:
In the following example, the user can log in successfully upon entering a valid password within three attempts. If the user enters an invalid password in the first or second try, the user will be prompted to re-enter the password. When the user enters the password incorrectly 3rd time, the action is taken, and the account will be blocked.
State Transition Diagram
In this diagram, when the user gives the correct PIN number, he or she is moved to the Access granted state. The Following Table is created based on the diagram above-
State Transition Table
| Correct PIN | Incorrect PIN | |
|---|---|---|
| S1) Start | S5 | S2 |
| S2) 1st attempt | S5 | S3 |
| S3) 2nd attempt | S5 | S4 |
| S4) 3rd attempt | S5 | S6 |
| S5) Access Granted | – | – |
| S6) Account blocked | – | – |
In the above-given table, when the user enters the correct PIN, the state transitions to Access granted. And if the user enters an incorrect password, he or she is moved to the next state. If he does the same 3rd time, he will reach the account blocked state.
Error Guessing
Error Guessing is a software testing technique where testers use experience and intuition to anticipate likely errors in the code. The technique is heavily based on the experience where the test analysts use their experience to guess the problematic part of the testing application. Hence, the test analysts must be skilled and experienced for better error guessing.
The technique counts a list of possible errors or error-prone situations. Then the tester writes a test case to expose those errors. To design test cases based on this software testing technique, the analyst can use past experiences to identify the conditions.
Guidelines for Error Guessing:
- The test should use the previous experience of testing similar applications
- Understanding of the system under test
- Knowledge of typical implementation errors
- Remember previously troubled areas
- Evaluate Historical data & Test results
Advantages and Limitations of Testing Techniques
Advantages:
- Improves test coverage and ensures broader validation of software functionality.
- Enhances defect detection by targeting high-risk or error-prone areas.
- Promotes systematic test design, reducing redundancy and overlap.
- Helps identify issues early in the SDLC, lowering overall project cost.
- Simplifies complex testing through methods like BVA and Equivalence Partitioning.
- Boosts software reliability and stakeholder confidence in product quality.
Limitations:
- No single technique guarantees complete defect detection.
- Some techniques depend heavily on the tester experience and judgment.
- May overlook integration, usability, or real-world performance issues.
- Time and resource constraints can limit thorough application.
- Certain methods offer limited automation support, reducing scalability.
How to choose the right testing techniques?
Choosing the right software testing techniques requires aligning them with project specifics to ensure efficiency and coverage. Factors like development model, risks, and resources guide the selection process. Being an expert software tester, I always recommend combining multiple techniques for optimal results. This prevents the chance of overdependence on a single method.
- Align with objectives: Match techniques to goals such as functionality, performance, or security needs.
- Assess risks: Prioritize high-risk areas with risk-based methods for targeted validation.
- Fit architecture and model: Opt for agile-friendly approaches in iterative or multilayer systems.
- Balance constraints: Consider time, budget, skills, and tools for feasible execution.
