NETWORK RELIABILITY EVALUATION DEVICE, METHOD AND PROGRAM

PROBLEM TO BE SOLVED: To learn how well an evaluation object communication network can maintain communication capability with an important communication node in the case where damage is large like a large scale fault and natural disaster.SOLUTION: The invention enumerates all the states of communication nodes and transmission links, calculates a probability Pi that the state S of each communication network becomes a certain state i using a probability PBthat a given communication node is in a fault state and a probability PLthat a given transmission link is in a fault state, determines whether or not a communication node is connected with a specified normal important communication node, calculates the communication scale Ei of the communication network when the state S of the communication network is the certain state i by using connection determination result between the communication node and the specified important communication node when the state S of the communication network is the certain state i, and an in advance prescribed communication scale Aof the communication node, multiplies the probability Pi by the communication scale Ei, and regards the sum of all the products as an expected value of the communication scale of the communication network.