Entry Point Isolation lets you build a component based on one of multiple entry points in a legacy program (an inner entry point in a Cobol program, for example) rather than the start of the Procedure Division. Component Maker extracts only the functionality and data definitions required for invocation from the selected point.
Entry Point Isolation is built into the main methods as an optional optimization tool. It's offered separately in case you want to use it on a stand-alone basis.