Online clustering reduction based on parametric and non-parametric correlation for a many-objective vehicle routing problem with demand responsive transport

•An online cluster approach transforms an 8-objective problem onto a 2-objective one.•A Pearson/τ-Kendall hierarchical cluster approach generates the 2-objective problem.•The approach coupled with a state-of-art algorithm is tested on a realistic dataset.•Comparing with the original formulation, the approach shows competitive performance.•The approach shows a favourable impact on search efficiency and computational cost.