Patent ID: 8024160

Claim:
A system for creating plans for procuring a commodity from a supplier and delivering to a prospective consumer, the system configured to solve a mixed integer programming problem that has as variables the number of delivery means for delivering said commodity according to a delivery schedule and the amount of said commodity purchased from said supplier, the system comprising: a memory; and at least one processor coupled to the memory and configured to implement: a dual solution computation unit that in a linear relaxation problem for said mixed integer programming problem, creates a qualification problem that is limited to at least one preset delivery schedule and computes a dual solution for said qualification problem; a schedule search unit that creates an objective function based on a constraint equation that constrains the dual solution of the constraint equations for the dual problem of said linear relaxation problem by the delivery schedules and searches for a delivery schedule exhibiting the constraints that violate the dual solution of said qualification problem by solving a dynamic programming problem having a recursive equation that shows the changes in said objective function value for the changes in the delivery states; a schedule adding unit that creates a new qualification problem by adding and setting said delivery schedule that has been found in said qualification problem with the finding of said delivery schedule as a condition and computes a dual solution to said new qualification problem using said dual solution computation unit; and an integer solution computation unit that computes and outputs the number of said delivery means and the amount of said commodity to be purchased by solving said mixed integer programming problem based on the solution of said qualification problem with said delivery schedule not being found as a condition.