Optimized investment planning for high-volume low-value buried infrastructure assets

This paper explores the potential savings that can be realized through the identification of optimal asset management business policies for small-diameter (25-50 mm) water communication pipes, which are installed between the customer's property boundary and the distribution main. The outputs from a geospatial mapping tool are used alongside a set of calibrated Weibull deterioration curves to drive a whole-life cost and performance analysis. Against this improved understanding of whole-life costs, an optimization algorithm is used to evaluate the trade-off between total expenditure (totex) and the prevention of future asset failures (serviceability) to identify the optimized investment policy according to the decision maker's priorities. Despite attracting an estimated yearly expenditure from water utilities operating across the developed world in excess of £4.42 billion per annum, the authors believe this is the first instance of optimizing communication pipe maintenance policies at the asset level in the industry. A case study is used to demonstrate the development and deployment of this methodology for South West Water (U.K.), whereby £8.5 million in savings and the prevention of up to 1,320 failures have been identified over a 25-year planning horizon.