Provided are a system design method, a system design system, and a system design reform assistance program. A system design apparatus includes a unit for receiving an analysis model which represents a system failure restoration sequence, a unit for identifying, from the received analysis model, a minimum combination of component failure which does not satisfy either a restoration time requisite or a necessary cost requisite and a unit for outputting the identified minimum combination of component failure. The unit for identifying the minimum combination of component failure further includes a unit for estimating the restoration time of a system, and a unit for estimating the cost required for restoration of the system.
