What approach to testing involves designing test cases based on requirements?

The approach to testing that involves designing test cases based on requirements is known as Requirements-based testing. This technique is grounded in the understanding of what the system is supposed to accomplish according to the documented requirements. By closely aligning test cases with these requirements, testers ensure that the final product meets the intended functionality and satisfies the needs of stakeholders.

In Requirements-based testing, each requirement is used as a foundation for creating test cases. This approach not only helps in validating that the software functions as intended but also aids in identifying any gaps in the requirements themselves. When requirements are clear, measurable, and testable, the resulting test cases are more likely to reveal whether the software meets the specified criteria.

The other approaches listed focus on different aspects of testing. Performance testing is concerned with how the application behaves under varying loads rather than validating against requirements. Integration testing focuses on the interactions between different system components, ensuring they work together correctly, but does not directly align with requirement validation. User acceptance testing aims to validate the product from an end-user's perspective to ensure it meets their needs and expectations but is conducted after the initial requirement tests.