2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference

Performance-based Contracts and Multi-objective Optimization Framework for Coordinated Infrastructure

Dr. Soliman Abu-Samra, KPMG Canada (Presenter)
Dr. Luis E Amador-Jimenez , Concordia University

One-third of Canada’s municipal infrastructure are in fair condition states and below. The aging of the deteriorating infrastructure networks, coupled with declining investment rates and uncertainty, led to higher failure rates and service disruptions accordingly. Furthermore, the spatial proximity and interdependency among the corridor infrastructure (i.e. roads, water, and sewer) remains a challenging issue for asset managers, due to the assets’ different deterioration mechanisms, service lives, rehabilitation strategies, etc. Canada’s infrastructure deficit is estimated between $110 billion to $270 billion and is annually increasing by $2 billion. Given the fact that the problem comprises multiple stakeholders with conflicting preferences upsurges the problem’s intricacy and complicates the decision-makers’ trade-off difficulty to reach consensus agreement. In the lights of those issues, this paper proposes an integrated performance-based contract and multi-objective optimization framework to ensure proper expenditures utilization, while maintaining adequate performance. The framework aids decision makers in reaching an optimal coordinated maintenance schedule. It revolves through three core models: (1) central database that contains detailed asset inventory for the infrastructure systems, (2) multi-dimensional computational models that integrate the contractual parameters with the asset management system, where five indicators namely; time, space, cost, risk, and condition were modelled for assessing the coordinated intervention plan performance over the conventional one; and (3) multi-objective optimization model that relies on a combination of mixed integer programming and goal optimization using Mosek engine to schedule the corridor interventions across the planning horizon. To demonstrate the system’s functionality, the system was applied to the town of Kindersley’s roads, water, and sewer networks over 25 years planning horizon. The results displayed huge savings in favor of the coordinated scenario as opposed to the conventional one. The coordinated scenario showed 1% condition improvement, 72% time savings, 63% less space consumption, 48% less LCC, and 67% less public disruption. Furthermore, the coordinated intervention program resulted in 67% fewer interventions as opposed to the conventional approach, saving an overall of 374 interventions across the 25 years, equivalent to 15 interventions annually, which drastically reduces the public disruption. In summary, the developed framework is an integrated contractual and asset management solution that assists both municipalities and maintenance contractors in taking informed decisions in the pre-contract and post-contract phases. It is an integrated solution for enhancing the expenditures’ utilization while improving the assets’ performance thresholds.