An algorithm for the stochastic delivery-and-pick-up vehicle routing problem with time windows as applied to surgical medical supplies

Objective: Develop a methodology for the delivery and pick-up route scheduling of medical surgical supplies under stochastic conditions. The technique was applied to a business operation case study in which it was necessary to fulfill specific delivery time windows under variable transportation and service time conditions. Materials and Methods: The method comprises a deterministic solution and a stochastic solution, both based on the Tabu Search metaheuristic. The stochastic approach was developed through a simheuristic in which Monte Carlo simulations are embedded in the procedure of the proposed metaheuristic. Travel time variation coefficients were applied to compare not only the two approaches, but also the best of them with the current procedure employed by the company under study. Results and Discussion: The indicators evaluated for all variation coefficients shows that the simheuristic performs better than both the deterministic approach and the procedure of the company. Conclusion: The implementation of the simheuristic in the routing problem is a feasible alternative that fits the stochastic conditions.