Decision Table Testing Tutorial
What is Decision Table Testing?
Decision Table Testing is a black-box test design technique that helps to identify test cases that can be derived from a set of conditions and actions. It is particularly useful for testing applications with complex business logic where multiple conditions can affect the outcome.
A decision table is a tabular representation of the different combinations of inputs and the corresponding actions (outputs) that should occur for those inputs. This method is beneficial in systematically covering all possible scenarios in the testing process.
When to Use Decision Table Testing
Decision Table Testing is ideal in the following scenarios:
- When there are multiple conditions leading to various outcomes.
- When the business rules are complex and need systematic validation.
- In situations where inputs can be categorized into different conditions.
- To ensure comprehensive coverage by identifying all possible combinations.
How to Create a Decision Table
Creating a decision table involves the following steps:
- Identify Conditions: Determine the relevant conditions that will influence the decision-making process.
- Identify Actions: Specify the actions that should occur based on the combinations of conditions.
- Define Combinations: List all possible combinations of the conditions and their corresponding actions.
- Construct the Table: Format the information into a clear table structure.
Example of a Decision Table
Let’s consider a basic example for a loan approval system where the decision depends on two conditions: Credit Score and Income Level.
Decision Table for Loan Approval
| Credit Score | Income Level | Action |
|---|---|---|
| High | High | Approve Loan |
| High | Low | Approve Loan |
| Low | High | Review Application |
| Low | Low | Reject Loan |
In this table, we can see the actions based on different combinations of credit scores and income levels.
Executing Test Cases from Decision Tables
Once the decision table has been created, test cases can be derived from it. Each row in the table represents a unique test case that can be executed. In the loan approval example, we can derive the following test cases:
Test Cases Derived from the Decision Table
- Test Case 1: Credit Score = High, Income Level = High → Expected Action: Approve Loan
- Test Case 2: Credit Score = High, Income Level = Low → Expected Action: Approve Loan
- Test Case 3: Credit Score = Low, Income Level = High → Expected Action: Review Application
- Test Case 4: Credit Score = Low, Income Level = Low → Expected Action: Reject Loan
Benefits of Decision Table Testing
Decision Table Testing offers several advantages:
- Enhances coverage by ensuring all combinations are tested.
- Helps in identifying missing test cases that may not be apparent.
- Facilitates communication among stakeholders by providing a clear visual representation of the logic.
- Reduces the risk of human error in the testing process.
Conclusion
Decision Table Testing is a powerful technique for designing test cases that can efficiently handle complex business logic. By systematically considering all possible combinations of conditions, it ensures comprehensive testing coverage. This approach not only improves the quality of the product but also enhances collaboration among team members.
By following the steps outlined in this tutorial, you can implement Decision Table Testing in your testing strategy effectively.