How do you identify if a result in a decision rule cannot be returned?

Test for Completeness:

Ensure that all possible conditions and outcomes are covered in the decision rule. This involves checking that there are no missing branches or conditions that could result in an undefined outcome.

Unit Testing:

Conduct unit tests to verify that all scenarios return the expected results. This helps in identifying any gaps or missing conditions in the rule.

References:

Pega Academy: Decision Rules and Validation.

Pega Documentation: Testing and Debugging Decision Rules.