Designing Cost-Effective Reliable Networks from a Risk Analysis Perspective: A Case Study for a Hospital Campus

Abstract

The unavailability of information and communication services due to network-related incidents may have a significant impact on large organizations. Network incidents can hence be viewed as a risk for organizations whose consequences are not accounted for by traditional network design problems. In this work, we address the problem of designing a reliable wired network from a risk analysis perspective. We propose a novel methodology for the quantitative assessment of the risk associated with network-related incidents in a hospital campus. We then define an optimization problem to find the topology that minimizes the network cost plus the expected loss over time attributable to the unavailability of corporate services to staff affected by network incidents. A case study illustrates our methodology and its benefits. Using available public information, we design the topology of a campus network for a large hospital where the cost of labor exceeds 200M€/year. The solution to our optimization problem is found through well-known genetic algorithms and provides a topology where network nodes with a higher impact on productivity exhibit higher reliability. As a consequence, the topology obtained reduces more than 95% (+392 000€) the expected annual lost profits when compared to common reduced-cost topologies such as the minimum-cost ring or the non-reliable minimum-cost tree, showing that investment in risk reduction pays off. Our contribution may be used by engineers to (re)design cost-effective reliable networks or by hospital managers to support decisions on updating present infrastructure based on risk reduction.