Method for managing network slicing resources in communication system and apparatus for the same

A first device in a communication system supporting network slicing, the first device comprising a first element supporting a network slice management slice (NSMS) function, a second element supporting a capacity planning function, and a memory storing at least one instruction executed by the first element and the second element, wherein the at least one instruction is configured to:

• configure at least one network slice with network resources and functions of a core network (CN) and a radio access network (RAN);
• receive, by the first element, a first message requesting the capacity planning of a first network slice instance (NSI) among the at least one network slice from a second device;
• obtain, by the first element, information required for the capacity planning;
• transmit, by the first element, a second message including the required information to the second element;
• perform, by the second element, the capacity planning for the first NSI based on the second message;
• transmit, by the second element, a third message including a result of performing the capacity planning to the first element;
• perform, by the first element, a reallocation operation or a modification operation of the first NSI based on the result of performing the capacity planning included in the third message;
• assign the first NSI to user equipment (UE);
• assign a second NSI to the UE;
• and
• share, by the first NSI and the second NSI, an access and mobility management function (AMF) of the communication system and a network slice selection function (NSSF) of the communication system, the AMF and the NSSF belonging to a common control plane of the communication system,
• wherein when the capacity planning is performed, network resources and functions constituting the first NSI configured with the network resources and functions of the CN and the RAN are optimized by operations including at least one of determining a relocation of the first NSI, or scaling up or scaling down of the first NSI.