Which conversion strategy allows for testing one module at a time?

The chosen answer, phased conversion, is correct because it is a strategy that enables the implementation of a new system incrementally, allowing one module or component to be brought online at a time, while the rest of the system remains operational. This approach ensures that users can test each module thoroughly in the live environment before fully committing to the new system, minimizing risks associated with a complete switch-over.

This method is beneficial as it allows for troubleshooting and adjustments to be made on a smaller scale, which can lead to improved system stability and user confidence. It can also facilitate feedback from users about each module, ensuring that any issues can be addressed before proceeding to the next phase of conversion.

In contrast, direct changeover involves a complete transition from the old system to the new one all at once, leaving no opportunity for testing individual components separately. Parallel running requires both old and new systems to operate simultaneously, which certainly tests the entire new system at once rather than allowing for individual module testing. Legacy conversion typically refers to the process of updating or replacing older systems, but it does not specifically pertain to testing modules in an incremental manner.