Considerations on search trees for solving large-scale assignment problems with priority order

This paper presents an approximation method for obtaining a feasible solution of a large-scale assignment problem with priority order. In the method, a set of integer variables to be changed is chosen by means of search trees, and then the integer variables are changed. Both maximum priority order and the number of resources with the maximum order become as small as possible. No efficient method has not been developed yet for solving the considered assignment problem. The proposed method is applicable to assignment problems whose cost coefficients cannot clearly be determined.