Designed solids are essentially containers for a collection of shapes that you add to and subtract from the solid. To place a designed solid, a designed equipment or a designed equipment component must first be placed in the model. Then, the designed solid is placed as a child of the designed equipment or the designed equipment component. You can then add shapes underneath the designed solid. You can have multiple designed solids under one designed equipment or designed equipment component. You can also have multiple designed equipment components under one designed equipment.