  The interdependency between different network layers is commonly observed in
Cyber Physical Systems and communication networks adopting the dissociation of
logic and hardware implementation, such as Software Defined Networking and
Network Function Virtualization. This paper formulates an optimization problem
to improve the survivability of interdependent networks by restructuring the
provisioning relations. A characteristic of the proposed algorithm is that the
continuous availability of the entire system is guaranteed during the
restructuring of dependencies by the preservation of certain structures in the
original networks. Our simulation results demonstrate that the proposed
restructuring algorithm can substantially enhance the survivability of
interdependent networks, and provide insights into the ideal allocation of
dependencies.
