PURPOSE: To form a rapid simulation program using a parallel computer by determining an optimum area division pattern by area division processing.

CONSTITUTION: Space area division processing 103 extracts 107 main operation with the highest load out of solution algorithm specified by input information 101 and executes area division 108 so that the extracted operation is most rapidly calculated. Namely, when the main operation is complete parallel operation capable of independent execution at respective grating points, the area is divided like blocks, and when the operation is data dependent parallel operation requiring the reference of the newest values of adjacent grating points, the area is divided like slices to improve the parallelism of operation. When the degree of parallelism is equal in both the operation, the volume of communication is reduced. Program output processing 104 changes the constitution of a formed program in accordance with the sort of main operation and forms the optimum program for various kinds of solution algorithm. Consequently, a rapid simulation program for a parallel computer can be formed for problems in a wide range.