The management system identifies a first event regarding a first node apparatus estimated to occur when a first maintenance work is performed on a first node apparatus based on maintenance work information that indicates a correspondence relationship between each maintenance work of one or more maintenance works for any of the plurality of node apparatuses and an event regarding a node apparatus to be the target of each maintenance work, which is estimated to occur when the maintenance work is performed. The management system identifies the range of effect and phenomenon of the case where the first maintenance work is performed on the first node apparatus, by performing simulation based on one or more rules indicating a correspondence relationship between one or more conditional events and a causal event and displays the identified range of effect and phenomenon.