A Multi-Method Framework for Sustainable Pharmaceutical Logistics in Vietnam: Integrating CVRP, Simulation, and ESG-Based Risk Management in the Mekong Delta

This study develops a staged multi-method framework for evaluating and improving pharmaceutical logistics in Vietnam’s Mekong Delta. The framework integrates Fuzzy-DEMATEL to identify the relative importance and causal relationships among feasibility factors, a CVRP formulated as an MILP model to optimize delivery routes, discrete-event simulation to validate operational performance under nominal conditions, post-tax cash flow analysis to assess financial viability, and FMEA to prioritize implementation risks. The results indicate that the optimized logistics configuration reduces total delivery distance by 9.28% relative to the existing distribution system while maintaining complete customer coverage. Under the assumptions adopted in the simulation model, the proposed configuration also maintains full order completion, completes all seven routes within the 12-hour delivery window, and records no backorders. Financial analysis suggests that the investment is viable, with an internal rate of return of 21.05% under the selected financing structure. The findings further identify operating costs and cost efficiency as the main drivers of feasibility, while natural-disaster exposure and regulatory change emerge as significant sources of risk. ESG-related implications are interpreted through proxy indicators of route efficiency, service performance, and governance-oriented control mechanisms, with implications for managerial decision support and future research.