1. A method, implemented by a computer system adapted to generate an Availability Management Framework (AMF) configuration in which service units of a service group are allocated to node groups and the node groups are allocated to physical nodes such that hardware redundancy for the service group is guaranteed, wherein each service unit is a unit of redundancy for services provided and protected by the service group, and each service unit includes one or more hardware components, software components, or a combination of hardware and software components, the method comprising the steps of: generating a node group set (NG set) of the node groups, wherein each node group includes a group of virtual machines and is to be mapped to a different host group that includes one or more physical nodes; generating collocation and separation rules for the virtual machines to specify which ones of the virtual machines are collocated in a same node group and which ones of the virtual machines are separated by different node groups; and mapping each service unit of the service group to a different node group in the NG set to thereby guarantee hardware separation in the AMF configuration for different service units of the service group and for the virtual machines allocated to the different service units.