A system, method, and computer program product are provided for instructing a virtual network function (VNF) to operate in accordance with one of a plurality of function definitions. In use, a virtual service including a plurality of VNFs is identified, the virtual service being a virtual service in a Network Function Virtualization (NFV-based) communication network, and at least one of the plurality of VNFs being capable of operating based on any one of a plurality of function definitions. Additionally, information associated with a current operation of the virtual service is received. Furthermore, it is determined which one of the plurality of function definitions the at least one of the plurality of VNFs is to operate, based on at least one of a plurality of policies and the information. Moreover, the at least one of the plurality of VNFs is automatically instructed to operate in accordance with the determined one of the plurality of function definitions.