A method is provided for estimating production capacity of a component mounting line for producing assembly boards. The component mounting line includes component-mounting-relevant devices coupled to one another, including a component mounter. Operator information is provided, which relates to an operator. Production-plan information is provided, which relates to a production plan for producing the assembly boards scheduled in the component mounting line. Based on floor-disposition information, production-lot information, event information, the operator information, and the production-plan information, a production capacity of the component mounting line is estimated. The floor-disposition information relates to a disposition of the component mounting line on a floor. The production-lot information relates to a time necessary for the component-mounting-relevant devices to produce the assembly boards. The event information relates to an event indicating that a work of the operator is necessary for the component-mounting-relevant devices and occurrence frequency indicating the number of occurrences of the event.