What is the purpose of cause-effect graphing in test case design?

The purpose of cause-effect graphing in test case design is to represent inputs and stimuli with their associated effects. This technique helps testers visualize the relationship between various conditions (causes) and their potential outcomes (effects). By systematically mapping these relationships, cause-effect graphing aids in identifying functional requirements that need to be tested.

The approach begins with identifying the causes, which are the different inputs or parameters that can influence the behavior of the system. Then, the effects are determined based on how those causes change the system's state or output. This clear and logical representation allows testers to design test cases that ensure all combinations of relevant inputs are considered, improving test coverage and effectiveness.

This technique is particularly helpful in complex systems where numerous variables can interact in multiple ways, leading to a wide variety of possible scenarios. By focusing on cause and effect, testers can efficiently prioritize and select test cases that will reveal critical defects while avoiding redundancy in testing.