PURPOSE: To reduce the number of neighborhood so as to shorten necessary time for a one-time improvement and to search them without falling into a local solution so as to efficiently obtain an aproximate and optimum solution.
CONSTITUTION: A correctness calculation module 1 extracting the relation of elements which can be improved based on an object function regarding a present solution, an NG holding module 8 accumulating and holding the relation of the elements which can be improved and elements replacing and relating with regard to the relation of elements which can be improved are moved. A neighborhood retrieving module 2 generating another solution and a changing check module 4 setting the generated another solution to be a new solution only when it does not include the relation of the elements held in the NG holding module 8 are provided. The new solution is repeated as the present solution so as to obtain the optimum solution.
YUGAMI NOBUHIRO
OISHI KAZUHIRO
