A power generation planning system for controlling on/off sequence of generators according to operational parameters includes an interface to receive the operational parameters including a power demand, state-data of the generators and operational histories of the generators from a power control system, a memory to store an objective function, a mixed-integer programming solver, generator parameters of each the generators and planning modules including a state-space representation module, a variable assignment module, a network flow module and a tight constraint module, a processor to perform the planning modules based on the operational parameters received by the interface. The processor is configured to construct decision diagrams for each of the generators by using the state-space representation module, generate arc-variables representing state-transformations of the generators by assigning binary variables to arcs of the decision, generate network flow constraints to represent feasible operations of each of the generators, generate tight constraints of each of the generators by using the tight constraint module and formulate a mixed-integer problem, solve the mixed-integer problem, by using the mixed-integer programming solver, based on the states-data of the generators, the network flow constraints and the tight constraints, and transmit on/off sequence data of each of the generators obtained from the solved mixed-integer problem to a power control system via the interface.