  Distribution systems are often crippled by catastrophic damage caused by a
natural disaster. Well-designed hardening can significantly improve the
performance of post-disaster restoration operations. Such performance is
quantified by a resilience measure associated with the operability trajectory.
The distribution system hardening problem can be formulated as a two-stage
stochastic problem, where the inner operational problem addresses the proper
sequencing of post-disaster repairs and the outer problem the judicious
selection of components to harden. We propose a deterministic robust
reformulation with two solution methods, an MILP formulation and a heuristic
approach. We provide computational evidence on various IEEE test feeders which
illustrates that the heuristic approach provides near-optimal hardening
solutions efficiently.
