Decision Table Testing is a software testing technique used to test system behavior for different input combinations. It’s especially useful in situations where the system’s response is dependent on a logical combination of multiple conditions. In this technique, a table format is used to represent and analyze different combinations of inputs and their corresponding outputs.
Key Aspects of Decision Table Testing:
- Tabular Representation: Uses tables to represent combinations of inputs and the expected outcomes.
- Multiple Conditions: Ideal for scenarios where there are several input conditions that determine an outcome.
- Systematic Approach: Ensures every possible combination of conditions is tested, leading to comprehensive test coverage.
How to Create a Decision Table:
List Conditions: Identify all the conditions relevant to the functionality you’re testing.
Determine Possible Outcomes: For each set of conditions, determine the expected system behavior or outcome.
Build the Table:
- The rows represent the conditions and their possible values.
- The columns represent unique combinations of conditions and the corresponding expected outcomes.
Fill in the Table: For each column, indicate the state of each condition (e.g., true/false, yes/no) and the expected outcome.
Advantages:
- Comprehensive Coverage: Ensures all possible combinations of conditions are tested.
- Clarity: Provides a clear visual representation of complex logical conditions and their outcomes.
- Reduces Redundancy: Helps in identifying and eliminating redundant test cases.
- Effective for Business Rules: Ideal for functionalities that rely on multiple business rules or logical conditions.
Limitations:
- Can Get Large: For functionalities with many conditions, the decision table can become very large, making it challenging to manage.
- Time-Consuming: Creating a comprehensive decision table can be time-intensive, especially for complex functionalities.
Example:
Let’s consider a simple example where a system provides a discount based on two conditions: whether the user is a “Premium Member” and whether they’ve made “Purchases over $100.”
The decision table would look something like:
| Premium Member | Purchases over $100 | Discount |
|---|---|---|
| Yes | Yes | 15% |
| Yes | No | 10% |
| No | Yes | 5% |
| No | No | 0% |
Each column represents a combination of conditions, and the corresponding rows indicate the state of those conditions and the expected outcome.
Conclusion:
Decision Table Testing offers a structured way to test functionalities that depend on multiple conditions. By visualizing conditions and outcomes in a table format, testers can ensure they’ve covered all possible scenarios and can easily communicate these scenarios to stakeholders. While it’s a powerful technique, it’s essential to manage the table’s size and complexity for maximum efficiency.