Sometimes requirements change very quickly, what can be done in those cases?

There is an expectation that the requirements should be determined early and should remain stable. Some approaches can be followed if these expectations are reasonable:

- Understanding how the requirements might change early in the stage can be done by working with project stakeholders early.
- The application should allow some adaptability to the changes that can occur in the requirments later.
- The code should be well documented and wriiten and commented. It makes notification of changes much easier.
- Rapid prototyping can be used to minimize changes.
- Some extra time should be taken into consideration in the case of changes.
- The new requirements should be moved to different phase while the original requirements should be in the original phase.
- The requiremnts that can be implemented more easily should be incorporated in the project first keeping the difficult requirements for future versions.
- The management and customer should keep in mind the effects that the changes in the requirements can incorporate.
- Automated test scripts should be made flexible.
- Test cases should be designed to be flexible.
- Ad hoc testing should be in focus more instead of detailed test plans and test cases.
- Minimize regression testing methods.

If the application has the functionality that was not in the requirements and if the functionality is not necessary, then it should be removed because it can have some unknown impacts and dependencies in the application which were not taken into account
by designer or customer. The management should be aware of the added risks as a result of unexpected functionality.