Decision Table Testing

Decision Table Testing

Decision Table Testing Decision table testing is an apparent and confident approach to analyze the test scenarios for complicated business logic.

We all know that the regulations and validations of a business take up a dominant portion of the requirements given by the customers. While examine how these requirements are represented and communicated to the unified project team by Business Analyst’s or customers, we come to know that utmost of such business rules and logic and are presented in a logical operation flow diagram.

A logical operation flow diagram for a compound requirement comprises of many branches, nodes, and decision boxes. Hopefully, we testers are expected to canvas all those branches and taste every nook and corner of such a complex logical tree. I have also faced such complex business discharge and tried many test case/test scenario preparation techniques for making the operation easier.

 Finally, I construct the decision table testing technique to be highly useful in this attitude. Here is how a decision table technique can make the test scenario preparation for complex business logic effortless.

                
Example: Writing test cases for a login screen using the Decision Table technique:

Let’s take a Decision Table example of below business conditions for a login screen.

The first step we do is to name all the branches and leave with numbers or alphabets as below.

1, 2, 3 are the leaves and a, b & c are the branches.

Points to Remember:-

•       All the validations stated in the decision boxes should be made of the columns on the table.

•       All the results (leaves) mentioned in the flow blueprint should be covered in the decision table.

•       All combinations of inputs needed to access a certain result shall be mentioned in the combinations column and can be included while writing the test cases.

•       After completing the decision table, one has to just justify whether all the branches and leaves in the logical tree are concealed. 

Advantages of Using Decision Table Technique:-

1) Any complicated business flow represented as a diagram can be easily concealed in this technique.

2) It provides abrupt confidence on the test cases. One need not have to review his own test cases multiple times to gain confidence.

3) Simple to understand. Anyone can make test cases from this decision table template.

4) Modify on the test cases and test scenario can be totally avoided, as it gives complete coverage at the first attempt.

Limitations of Using Decision Table Technique: 

Convinced test case preparation techniques like Boundary value analysis, equivalence partitioning cannot be precisely accommodated in this template. But, one can note it down in the combinations column and use them while writing test cases.

Why can’t other test case design techniques for business logic prove to be useful as Decision Tables?

1) Boundary value analysis and Equivalence class partitioning are meant for figure ranges and length. Both of these techniques alone cannot ensure 100% test coverage for business laws.

2) Error guessing is more about the action. Though experience is required, it cannot prove to be everything.

3) With state transition testing technique, one can protect that all parts of the logical tree are coated but it does not advocate document or artifact as decision table technique safeguard coverage with a decision table

For writing test cases for business logic, it is desirable to follow the below steps to prepare test cases so as to ensure maximum test coverage:

Step #1) Use a decision table test case design technique to promote 100% logical coverage.

Step #2) Boundary value analysis and Equivalence partitioning for covering assorted ranges of inputs.

Step #3) Combinations and permutations for field level affirmation (though not all permutations are required).

Step #4) Error guessing (apart from the errors that can be identified from the above three steps) with experience as a closing touch

With the right combination of all these techniques, tester will be able to determine almost all test scenarios for any application under test.