A decomposition approach to unit maintenance scheduling

The authors present the results of duality theory-based decomposition of the thermal generator unit maintenance scheduling problem. In the first stage, a master problem is solved to determine a trial solution for the maintenance schedule decision variables. In the second stage, a subproblem calculates the minimum operating cost while satisfying the reliability constraints for each week of the study period. New constraints for the master problem, similar to Benders cuts, are generated from the solution of the subproblem using duality theory, so that an improved maintenance schedule can be obtained. The procedure continues until an optimal or near-optimal solution is found