How to Effectively Test Decision Tables: A Comprehensive Guide
Published on: 2024-08-10 18:36:09
Testing decision tables is crucial for ensuring that they guide decision-making accurately and effectively. This article outlines the steps for testing decision tables, highlights key considerations like conflict checks, and showcases advanced functionalities available in modern decision engines.
Steps for Testing Decision Tables
1. Identify the purpose
The first step in testing a decision table is to understand its purpose. Determine what decisions the table is meant to support and what outcomes are expected from various conditions.
Example: A decision table for loan approval may include conditions such as credit score, income level, and employment status. The table's purpose is to determine whether an applicant is approved or rejected based on these factors.
2. Draft test cases
Create test cases based on the conditions and actions specified in the decision table. For each condition, develop corresponding test data. Ensure that the test cases cover all possible combinations of conditions and actions.
Example: For a loan approval decision table with conditions for credit score (Good, Fair, Poor) and income level (High, Medium, Low), draft test cases for each combination, such as (Good, High), (Fair, Medium), and (Poor, Low).
3. Execute test cases
Run the test cases and record the results. Check that the decision table processes each combination of conditions correctly and produces the expected outcomes.
Example: If the combination (Good, High) should result in approval, verify that this outcome is correctly achieved when the test case is executed.
4. Verify results
Compare the actual outcomes with the expected results. Confirm that the decision table operates correctly for all specified conditions. Note any discrepancies for further analysis.
Example: If the decision table specifies that (Poor, Low) should result in rejection, verify that this result is consistently produced.
5. Modify and repeat
Adjust the decision table based on the results of the tests to address any issues. Repeat the testing process to ensure that all problems have been resolved and the table meets its objectives.
Choosing the Best Testing Approach
Action-result not always required
For decision tables where a result is not mandatory for every value, prepare valid ranges of values and a synthetic data sample with all possible combinations. Test the table using this sample to ensure it handles all potential inputs accurately.
Example: If the decision table does not need to cover all combinations, focus on testing key ranges of credit scores and income levels.
Action-result always required
For tables that must always provide a result, identify all possible conditions and actions. Create test data for each combination, including edge cases and extreme values. Use manual or automated testing tools to ensure comprehensive coverage.
Example: If the decision table must provide an outcome for every combination of conditions, test edge cases such as minimum and maximum credit scores and income levels.
Addressing Gaps in Decision Results
Decision gaps
Investigate any decision gaps where actions are missing. If needed, add a catch-all row with a wildcard character to cover any conditions not explicitly addressed.
Example: If certain combinations of conditions are not covered, add a catch-all row to handle unexpected or missing combinations.
Catch-all rows
Implement catch-all rows for default or error cases. Ensure their placement in the table is considered carefully to prevent unintended precedence issues. Test these rows to confirm they manage unexpected inputs appropriately.
Example: A catch-all row with a wildcard condition could provide a default action for any undefined input, such as "Review manually."
Handling Multiple Actions for a Single Condition
Order of actions
Determine if multiple actions linked to a single condition need to be executed in a specific sequence. Define the order in the decision table if necessary. Test to verify that actions are performed in the correct order.
Example: If a condition triggers actions such as "Notify customer" followed by "Update database," ensure that the actions are executed in the specified order.
Testing Decision Flows
Complete flow testing
When the decision table is part of a larger decision flow, ensure that all components—including decision tables, decision points, and final actions—are tested. Validate the entire flow to confirm that all interconnected elements work together seamlessly.
Example: In a loan approval process, test the flow from initial application through decision-making to final approval or rejection.
Conflict Check
Identifying conflicts
Evaluate the decision table for conflicts where multiple conditions might lead to contradictory actions or results. Conflicts can undermine the accuracy and reliability of the decision table.
Example: If two conditions could both result in approval but under different criteria, ensure that the decision table handles these overlaps correctly.
Advanced functionality
Modern decision platforms, such as Decisimo, provide advanced conflict-checking functionality. These engines analyze the decision table for overlaps and inconsistencies, automatically detecting conflicts between conditions and actions. Utilizing such advanced features helps ensure that the decision table operates without contradictions and maintains decision integrity.
Example: Decisimo's conflict-checking feature might highlight where overlapping conditions could lead to conflicting actions, such as approving and rejecting the same application based on different criteria.
Resolving conflicts
Use conflict resolution strategies, such as prioritizing certain conditions or actions, to address conflicts. Ensure that the decision table manages conflicts effectively, leveraging the conflict-checking capabilities of advanced engines when available.
Example: If a conflict is identified between two conditions, adjust the decision table to prioritize one condition over the other to ensure consistent outcomes.
Conclusion
Thoroughly testing decision tables involves validating all conditions, results, and interactions, while addressing gaps and conflicts. By following these steps and utilizing advanced functionalities like those offered by platforms such as Decisimo, you can ensure that your decision tables support accurate and effective decision-making processes.
