A method and apparatus for instantiating network slices using connectivity and computing resources, is provided. Information regarding connectivity and computing resources for supporting network slices is used to identify shared risk groups. Each shared risk group includes those resources expected to be disabled by a common failure event. A first set of functions, such as virtual network functions, belonging to a network slice, is instantiated on a first subset of the resources. The union of all shared risk groups which include at least one of the first subset of resources is disjoint from the union of all shared risk groups which include at least one of a second subset of resources. The second subset of resources is allocated for instantiating a second set of functions which are redundant with the first set of functions. As such, redundant network slices and/or functions thereof can be provided which are robust to failure.