In this diagram, the states are shown in circles, and the transitions are the arrows. There are 3 test cases based on this diagram:
- Test cases 1: The user enters correct payment details the first time and then is able to upgrade to Paid Plan successfully
- Test case 2: User enters invalid payment details the first time and tries the second time with valid payment details. The user is then able to upgrade the plan.
- Test case 3: User enters invalid payment details for both attempts. The user will then be redirected to the Contact Support page.
By using this technique, testers can cover all conditions and results through a visualized diagram. However, when the system is large or does not have a sequential order, this technique will not be appropriate.
While Equivalence Partitioning and Boundary Value Analysis mainly focus on the user interface to verify if the application responds to the same behavior for a range of input, Decision tables and State transition testing are more suitable for business logic or business rules when the system responds differently. Besides learning how these Black Box testing techniques work, testers need to determine how to flexibly apply them in real projects when it comes to the size of the application and the complexity of inputs and combinations.