CAUSE INFERENCE REGARDING NETWORK TROUBLE

To appropriately determine a trouble occurring in a network. A network system acquires an output obtained when input data including an index acquired from a target network is input to a cause inference model. The cause inference model is one of a plurality of cause inference models. The plurality of cause inference models respectively correspond to a plurality of groups into which a plurality of networks have been classified and are trained based on training data including input data including an index acquired for each corresponding group and ground truth data indicating a cause of a trouble. The input cause inference model corresponds to a group to which the target network of the plurality of networks belongs. The network system executes a process for responding to a trouble that has occurred in the target network based on the output of the trouble cause inference model for the target network.