An operational support device sets an execution time of overfiring serving as an operation of a power generation facility at an output higher than a rated output. The device includes a life index value acquisition unit that acquires a life index value at a start time, the life index value being an index indicating a life of the power generation facility and changing in value in one direction with the output of the power generation facility; an output pattern setting unit that sets an output pattern per unit time of the power generation facility from the start time to a stop time based on the life index value such that the life index value reaches a predetermined value; and an overfiring setting unit that sets, based on the output pattern, a time in a period from the start to the stop time at which the overfiring is to be performed.