To explore the capabilities and implications of these tools, a sample application was developed using the ICS BuilderXcessory tool. At minimum, any change would require using the BX tool to modify the screen display. This would be followed by the subsequent step for code generation and building. Cloning might be rather fast, but any future changes could require a serious maintenance effort to keep the clones all working. Over the course of the interface's lifetime, changes will occur to the presentation mechanisms - but the underlying data model remains essentially intact.
User interaction can change without necessarily impacting either the data's derivation or display.
The MVC approach was used as the basis for the StarView application. StarView is being developed by the Space Telescope Science Institute as the user interface to the Hubble Data Archives. The use of the MVC in StarView has given us a significant amount of latitude in keeping StarView flexible enough to accommodate changes to the database or forms requirements, without having to re-visit the code. This approach has also allowed the development team to quickly adapt StarView from a CRT display to the use of X Windows. Yet both versions of the application continue to share common database and form definitions.