Generating policy rules by: storing a job execution schedule containing complete schedule times of jobs; and storing a job execution condition describing an execution limit condition and a method of evaluating an amount of loss incurred when the execution limit condition is not met, for the plurality of jobs; wherein a rule generation tool, under control by a processor of a policy rule generator, executes: evaluating an amount of loss by referring to the job execution schedule and the job execution condition when a special action is taken in the event that a special event occurs in a special one of the jobs at a special time; and evaluating an amount of loss in respect of all of plural actions prepared for the special job and the special event at the special time and determining an action which minimizes the evaluated loss amount thereby to generate a policy rule.