A management device for selecting a network function (NF) is provided. The management device includes memory, including one or more storage media, storing instructions, at least one transceiver, and at least one processor communicatively coupled to the transceiver and the memory, wherein the instructions, when executed by the at least one processor individually or collectively, cause the management device to transmit a request message to each NF of a plurality of NFs connected to the management device, receive at least one response message from at least one NF of the plurality of NFs after transmitting the request message to each NF, obtain connection state information of each NF based on the request message transmitted to each NF and the at least one response message from the at least one NF, detect a fault NF from among the plurality of NFs based on the connection state information, and perform an NF selection procedure by configuring a restriction for a new call connection using the fault NF.