Imagine that you collected geographic data in one schema and you want to provide it in some other schema. For many of us, this only happens pretty much all of the time.
For example, maybe your organization has an enterprise database which stores all the information that you have about recent, active faults. Now you want to provide that data as a WFS service with fields that conform to the ActiveFaults template being used by the AASG Geothermal Data System. Perhaps you store all your geologic map data in such a database and you want to convert it into FeatureClasses that fit into NCGMP09-style geodatabases.
Here's a nice way to convert your data formats in such a way that you only have to do it once. You can continue to make changes to your data just like you always have, and there will always be a featureclass hanging out there in the new schema which conveys the most up-to-date information that you have. The pre-requisites are: