A COMPARISON OF GEOGRAPHIC INTERVENTION GROUPING METHODS FOR INFRASTRUCTURE INTERVENTION PLANNING ACROSS MULTIPLE NETWORKS

Interventions on infrastructure networks in municipalities cause disruptions to the service provided by the network that requires the intervention. They also cause disruptions to the service provided by other networks that have to be at least partially shut down so that the intervention can be executed. Due to these effects, there is substantial benefit to be obtained by grouping interventions on all networks that are spatially close to one another, i.e. work programs for spatially close networks should be developed together. This benefit is principally due to reduced interruption to services and reduced costs of intervention. The challenge of determining such combined optimal work programs is made more difficult as it requires quantification of the value of lost services, which depends on how different stakeholders value the services as well as how the services are interrupted. In this paper the difference between two methodologies to be used to develop work programs on spatially close infrastructure networks is shown: 1) a traditional methodology based on a grid-cell based grouping method, and 2) a methodology based on a combined topology / Voronoi cell / density based clustering of interventions. Both methodologies exploit recent developments in the area of critical infrastructures and GISs. The differences are illustrated by using both methodologies to determine combined work programs for five spatially close infrastructure networks (electricity, gas, water, sewage, roads) in a municipality with approximately 1'500 inhabitants. The advantages and disadvantages of each are discussed.