Abstract: The multi-period operational planning for the boiler steam system was formulated as a mixed-integer nonlinear program (MINLP). The objective function accounted for both the operating costs for each period and changeover costs for start-up/shut-down of boilers between periods of operation. A sub-section method was proposed for solving the MINLP problem with the line-up competition algorithm (LCA) coupled with dynamic programming approach. The computation time for the method was proportional to the number of periods, and global solution of the MINLP was guaranteed. The effectiveness of the proposed method was illustrated with two examples.