When you create an Enterprise Developer project for an IMS application, you use the provided Mainframe Subsystem Application template. This creates the necessary infrastructure that enables the application to run on an enterprise server as if the application were running on an actual mainframe.
Once you have created the project, you then configure it as an IMS application by setting appropriate project properties.
You then create objects (items) for or add objects to the project, including programs, copybooks, MFS screens, PSBs, and DBDs.
From the Enterprise Developer project, you continue developing the application using the provided program/code editor. You can also compile all or part of the application, generate DBDs, PDBs, and MFS files, and deploy the application.