To design an overlay structure, you should select those control sections that receive control at the beginning of execution plus those that should always remain in storage; these control sections form the root segment. The rest of the structure is developed by determining the dependencies of the remaining control sections and how they can use the same virtual storage locations at different times during execution.

The remainder of this section discusses control section dependency, segment dependency, the length of the overlay program, segment origin, communication between segments, and overlay processing.