To propose optimal material combination by employing a deformed Best-Fit procedure and preventing the last material from being improperly allocated.
Materials are sequentially selected, and the optimal allocation is determined as preliminary allocation by combining the materials that can be allocated. The Best-Fit procedure deformed therefor is employed. The same process is applied to the other materials. The process is performed under a condition that the longest product is always allocated first to the material. A plurality of preliminary allocation results are compared to employ the best one of good yield as product allocation data. The processes are repeated to detect the timing to complete it by two more processes. In the two more processes, a plurality of allocation pattern candidates are acquired and compared, and the optimal allocation pattern is employed.