Tips for identifying functional test cases.

1. Sufficient Test Cases, Positive and Negative have been identified for each use-case scenario.
2. Test Cases address any business rules implemented by the use cases, ensuring that there are test cases inside, outside and at the boundary condition / value for the business rule.
3. Test Cases address any sequencing of events or actions, such as those identified in the sequence diagrams in the design model or user interface object states or conditions.
4. Test Cases address any special requirements defined for the use case, such as minimum / maximum performance, sometimes combined with minimum / maximum loads or data volumes during the execution of the use cases.