Descriptive Design Structure Matrices for Modelling Infrastructure Interdependencies in Community Recovery

Abstract

Infrastructure interdependencies have significant impacts on the recovery of community sectors in the post-disaster period. The focus of this research is to identify critical community sectors and to understand how the interactions between these infrastructure sectors drive the recovery process. Descriptive Design Structure Matrix (DDSM) was used to qualitatively describe the interactions between infrastructure sectors. A 3-tier Hypothesis DDSM was developed to identify and define the interactions between community sectors, that was compared with a case-study DDSM to compare and validate the reported interactions, based on which a final DDSM was developed with 16 infrastructure sectors to qualitatively describe the interdependencies between community infrastructure sectors.

DSM Modelling analysis revealed the critical infrastructures and the critical interactions that influence the recovery of a community. The following insights were drawn from the DSM model and could constitute the core elements of a normative approach to community recovery that could be used when developing recovery strategies for an efficient and speedy recovery in the post-disaster period: 1. The 5 most ‘critical’ infrastructure sectors based on their importance for community recovery are – Commerce, Governance, Power Distribution and Generation, Road Transportation, and Workforce Population. 2. The primary focus in the recovery period should be on the restoration of infrastructure services that are required for the recovery of other infrastructures, even if they are not the metrics used to measure recovery performance. 3. To speed community recovery, infrastructures must recover in ways that build the capacity of their dependent infrastructures. 4. Recovery planning for short-term and long-term recovery should reflect the differences between the two stages of recovery.

The DDSM can be a useful tool for community leaders to understand the impact of infrastructure interdependencies in the post-disaster period and to develop strategies that consider these interactions for a speedy and resilient recovery. The tool is expected to compliment the use of proven methodologies (such as PDNA) and to provide a systematic and a structured approach to prioritize sequencing of resources and to analyze the impact of specific resource allocations to check if the recovery policies being implemented will have the required impact.