Software Maintenance

Corrective maintenance: Changes made to correct a system after a failure has been observed (usually) after general release)

Adaptive maintenance: Changes made to achieve continuing compatibility with the target environment or other systems.

Perfective maintenance: Changes designed to improve or add capabilities

Preventive maintenance: Changes made to increase robustness, maintainability, portability, and other features

Rapid Iterative Development

The extreme programming approach requires that a test be developed for each class and that this test be re-run every time the class changes.

First Step of Integration

Re-running accumulated test suites, when new components are added to successive test configurations, builds the regression suite incrementally and reveals regression bugs.

Compatibility Assessment and Benchmarking

Some test suites are designed to be run on a wide range of platforms and applications to establish conformance with a standard or to evaluate time and space performance. These test suites are meant for regression testing, but not intended to reveal regression bugs.