The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present disclosure further relates to a method by a session management function (SMF) in a network including a session that is established via a first user plane function (UPF). The method includes determining whether to change the first UPF to a second UPF, and transmitting, to a terminal via an access and mobility function (AMF), a first message including a maintain time of the session established via the first UPF, when the first UPF needs to be changed.