Each 'bubble' in the data flow diagram can be represented by an IC card. The IC card, as well as other visual representations such as the CRC card, is easily understood by the user and the designer.

The IC card can be expanded and replaced by other IC cards. Correspondingly, the 'bubble' can also be expanded and replaced by a more complex data flow diagram.

The IC cards lead to object-oriented design (OOD) of the modules (or classes). Each module corresponds to one (or a group of) IC cards.