Problems FEPI can solve

Many users have CICS® and IMS applications that they want to use differently; for example, to extend their use by incorporating them into other applications. But they cannot change the way the applications are used because they cannot change the application programs.

FEPI allows existing CICS and IMS application programs to be used in different ways, in different combinations, in different environments, and on different systems, without changing them, because it provides a simple integrated interface to these programs. FEPI also lets you write new programs that add function to old programs.

There are many reasons why existing application programs can't be changed. Perhaps the application was bought in a package, so that you don't have the source. Perhaps someone else owns the application; perhaps it runs on someone else's system. Perhaps the source has been lost, and there's no one around who knows the program well enough. Perhaps the program logic is so complex that any changes are considered too dangerous.

Or perhaps it is an application that was written for one specific environment, such as IBM® 3270 information display systems, and you want to use it for another, or you want to extend its function. You don't want to change the application, because it must still work with the 3270s.

To get around this, you can run the existing application unchanged and provide a front-end program to interface to it. Using FEPI, a front-end program can simulate a terminal. This means the program can gain access to applications written to support that terminal. That program can then use the existing applications, and the existing application is unaware that anything has changed.

Therefore, the existing application can be used differently without being changed in any way. The changes are in the simulating program. For example, newly written applications can collect data from several existing applications. The existing applications can be on the same system as the simulating program, or on a different system.