An access path management method for a storage network system where a plurality of paths are formed between a data storage system and a host computer which uses the data storage system, an integrated management server monitors port resources constantly. When a port overloads or when a failure occurs in a port, a previously unavailable port is made available and then an access path passing through this port is created to thereby secure a necessary bandwidth. When the load on a port is reduced, an access path that passes through this port is deleted to free a part of the bandwidth, and then the port that is currently in use is invalidated. A license management server for managing how the ports are used, charges by counting in only the length of time during which the port is in use.