Analytical versus numerical long-term cost modelling of coordinated rehabilitation strategies for water distribution, sewer, and road networks

Urban water, sewer, and road infrastructures are simultaneously facing renewal demands, necessitating more cost-efficient rehabilitation strategies. Coordinating interventions across co-located assets can lower long-term expenditures, yet strategic-level modelling approaches remain limited. This study evaluates two such methods: joint cohort survival analysis (JCSA), which models either separate or systematic coordination, and the multi-utility rehabilitation modeller (MURM), which introduces a coordination window to represent intermediate policies. Both methods were applied to residential street cohorts constructed in Luleå, Sweden, during 1965–1975. The results indicate that JCSA and MURM produce consistent outcomes under no-coordination and systematic coordination scenarios. In contrast, under moderate coordination, MURM predicts substantially lower accumulated capital costs (€50.5 m) than JCSA (€58.8 m), corresponding to a 12–17% reduction. These findings demonstrate the analytical advantages of MURM for strategic asset management, offering decision-makers a more realistic representation of coordination policies and their long-term financial implications.