The family diagram (milieu diagram) is designed to visualize the life history of a child as a member of this family. Changes in structure of the family correspond with changes in the diagram. Temporary separations are indicated by hatching. The vertical columns, reading from lelt to right, represent talendar year — organisations which are in touch with the family — housing-housemates — parents and their working situation — children. The use of the family diagram has been demonstrated with the facts from a case history.