Network function virtualization is quickly gaining acceptance as the new approach to delivering communication services. The promises of greater flexibility and dramatically reduced time to introduce new services coupled with the cost advantages, are driving communications service providers(CSP) around the world to begin deploying NFV-based services. An NFV operation system is divided into the NFV Orchestrator (NFVo), VNF Manager (VNFM), and VIM (Virtual Infrastructure Manager) subsystems in accordance with the ETSI standard, and the VNFM is defined as the system provided by the VNF manufacturer. In this paper, we present a generic VNF management system for administration and operation of the NVF” under the following structure and to specify the Or-Vnfm, Ve-Vnfm and Vi-Vnfm interfaces, with the goal of developing a generic and scalable VNFM to support various VNFs.