FT-KMEANS: A Fast Algorithm For Fault-Tolerant Facility Location

The design of supply networks that are resilient to disruptions has recently attracted considerable attention. We consider supply networks where a set of clients are served from a set of facilities. The cost of serving a client from a facility is proportional to the distance between the client and the facility. When a facility becomes unavailable due to a disruption, its clients are reassigned to the closest facility that is still operating. The network is resilient when disruptions cause only moderate reassignment costs. One way to design a resilient network is to solve the fault-tolerant k-median problem. Under this problem, a set of k facilities (medians) must be located such that the sum of distances from clients to their r nearest facilities is minimized. This paper introduces a new algorithm for large-scale instances of this problem. Using a benchmark instance with close to 10,000 clients, we demonstrate that our heuristic consistently devises better solutions than the state-of-the-art approach in much shorter running times.