Abstract: A solid model is created from a plurality of incomplete drawings. Line segments or curves on each view are calculated from two-dimensional data of a three-view drawing. A wireframe model is created on the basis of the calculated line segments or curves. The wireframe model is corrected by comparing edges of the created wireframe model and the line segments or curves. The corrected wireframe model is converted into a cell-decomposition model. Conditions establishing the line segments or curves as edges of the cell-decomposition model are set by Boolean expressions. A solid model is synthesized on the basis of combinations of cells which are solutions of the expressions. If no solution exists even if the expressions are solved, candidate models are synthesized on the basis of any combination of cells. The synthesized candidate models are displayed in the descending order of the degree of similarity.