PURPOSE: To improve the reliability of data and to simplify data operation by securing previously defined data structure for actual data, and handling the substance and relation systematically.

CONSTITUTION: Attributes 1 as a set of value added to the substance and relation, substance 2 having a local name defined, relation 3 showing coupling between plural substance kinds, and dependency relation determined by the presence of other substance are defined as data components which constitute the structure of the substance and relation. A figure shows an example of data operation. The attributes are a1 and a2; a1 can be added to a substance kind e1 and a2 can be added to a relation kind r2. The relaton kinds are r1 and r2; r1 can couple both rolls r11 and r12 with the substance e1 and r2 can couple e1 with the roll r12 and e2 with the roll r22. Dependency relations are w1 and w2; master sides are w11 and w21 and slave sides are w12 and w21.