What is Software Testing Technique?
Software Testing Techniques are systematic approaches used to design test cases to identify defects in software applications. These techniques help testers ensure that software behaves as expected under various conditions.
5 Important Software Testing Techniques
1. Boundary Value Analysis (BVA)
- Purpose: To test the boundaries of input domains because errors often occur at the edges.
- How it works: Test cases are designed to include the minimum, maximum, and values just inside and outside the boundaries.
- Example: If an input field accepts values from 1 to 100, test cases would include 0, 1, 2, 99, 100, and 101.
2. Equivalence Class Partitioning (ECP)
- Purpose: To reduce the number of test cases by dividing input data into classes (partitions) that are expected to behave similarly.
- How it works: Inputs are grouped into valid and invalid equivalence classes. One test case is selected from each class.
- Example: If an age input field accepts values 1 to 100, we can divide the values into three classes:
- Valid class: 1 to 100 (e.g., test with 25)
- Invalid class (below range): Less than 1 (e.g., test with -5)
- Invalid class (above range): More than 100 (e.g., test with 150)
3. Decision Table Based Testing
- Purpose: Uses a table format to represent different combinations of inputs and their corresponding expected outputs.
- Useful when a system has multiple conditions affecting outcomes.
- How it works: A decision table is created with conditions (inputs) and corresponding actions (outputs). Test cases are derived from the combinations of conditions.
- Example: A login system that checks:
- Correct username & password → Access granted
- Incorrect username & correct password → Access denied
- Correct username & incorrect password → Access denied
- Incorrect username & incorrect password → Access denied
4. State Transition Testing
- Purpose: Used when a system behaves differently based on previous actions (states).
- How it works: Test cases are designed to validate transitions between states based on inputs.
- Example: ATM system:
- Card inserted → Enter PIN → Correct PIN → Access account
- Card inserted → Enter PIN → Incorrect PIN (3 times) → Card blocked
5. Error Guessing
- Purpose: To identify potential errors based on the tester’s experience, intuition, and knowledge of the system.
- There are no formal rules, but testers use their judgment based on past defects.
- How it works: Test cases are designed to target areas where errors are likely to occur, such as invalid inputs, edge cases, or poorly documented features.
- Example: In a registration form, the tester might guess that leaving the email field blank, entering an invalid email format, or exceeding the character limit could cause errors.
Summary Table:
| Technique | Purpose | Key Focus Area |
| Boundary Value Analysis (BVA) | Test boundaries of input domains | Edge values and boundaries |
| Equivalence Class Partitioning (ECP) | Reduce test cases by grouping similar inputs | Valid and invalid input classes |
| Decision Table-Based Testing | Test complex business logic with multiple conditions and outcomes | Combinations of conditions/actions |
| State Transition Testing | Test systems with state-dependent behavior | State transitions and inputs |
| Error Guessing | Identify errors based on experience and intuition | Likely error-prone areas |
