The concept of family molding is derived from the family mold. A family mold is a multi-cavity mold with a common mold plate shared across the cavities. It is designed to produce multiple parts with different cavity configurations in a single shot.
A standard multi-cavity mold produces several identical parts in one cycle, such as four identical buttons, to maximize output for a single component.
A family mold produces several different parts of an assembly in one cycle, such as one top enclosure, one bottom base, and two side buttons, so you can make all assembly components in a single shot.