A network management entity configured to: deactivate a Network Slice Instance without releasing network resources previously allocated to the Network Slice Instance; and subsequent to deactivating the Network Slice Instance, activating the Network Slice Instance using the network resources previously allocated to the Network Slice Instance. A Network Slice Management Function (NSMF) perform slice specific Lifecycle Management (LCM) for a Network Slice Instance (NSI) based on Communication Service Instance (CSI) requirements is also disclosed. Customer Service Management Function (CSMF) for receiving service requirements from a Service Manager (SM) and transmitting the CSI requirements a Network Slice Management Function (NSMF) is also disclosed.