Yagmur, EceYuce, Muserref2026-04-102026-04-1020262090-44952090-4479https://hdl.handle.net/20.500.13091/13116https://doi.org/10.1016/j.asej.2026.104065Parcel lockers have emerged as efficient solutions for last mile logistics, enhancing delivery performance, reducing costs, and eliminating environmental impacts. Their success, however, heavily depends on optimal location selection. This study addresses the parcel locker site selection problem in Istanbul, a megacity characterized by high population density, using a Geographic Information Systems (GIS) based hierarchical framework. At the macro level, Fuzzy Analytical Hierarchy Process (FAHP) and Weighted Sum Method (WSM) were employed to prioritize and identify suitable subregions for deployment. At the micro level, spatial and Point of Interest (POI) data were integrated to capture detailed urban features. Within this scope, criterion weights were determined using the MEREC approach, providing an objective evaluation. Alternatives were then assessed with TOPSIS, WASPAS, and VIKOR, and results were aggregated through two ensemble ranking methods: Half Quadratic programming and Spearman's correlation based ranking. Furthermore, a sensitivity analysis was performed to evaluate the stability of the rankings against fluctuations in criteria weights. The Spearman rank correlation coefficients ranged between 0.92 and 0.98 across eight scenarios, statistically validating the robustness of the proposed framework and ensuring that the identified ensemble rank remains consistent across all scenarios.eninfo:eu-repo/semantics/openAccessSpatial AnalysisWaspasLast Mile DeliveryMerecWelsch Loss FunctionTopsisVIKOROverture Maps FoundationArticle10.1016/j.asej.2026.1040652-s2.0-105032564798