Attack scenario information describes each state of an information processing system to be attacked and an attack scenario including a chain of actions that can be taken in the state, an action that transitions from a first state to a second state is obtained with reference to state information, action information, and attack tactics information, a reward of the action is obtained with reference to reward information, the action information, and the attack tactics information, an expected reward of the reward of the action that transitions from the first state to the second state is obtained with reference to success probability information, the highest expected reward is set as a state value of reinforcement learning of the first state among the expected rewards of the action, and the attack scenario is generated by the reinforcement learning.