Network management apparatus, method, and program

A network management device comprising:

• failure influence calculation circuitry configured to calculate, for each of a plurality of buildings corresponding to an upper layer of a network, an influence of a failure in communication including an occurring failure and an influence of the occurring failure on another building corresponding to a lower layer of the network when a condition that the failure occurs in communication in one of the buildings corresponding to the upper layer of the network and each accommodating a communication facility is applied;
• and
• priority calculation circuitry configured to calculate, for each combination of a plurality of buildings in which the failure has occurred, a priority of a candidate for a building to be restored from the failure among a plurality of buildings when a condition that the failure occurs in communication in the plurality of buildings corresponding to the upper layer is applied on a basis of the influence calculated by the failure influence calculation circuitry.