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

Objective: The objective of this study was to develop a methodology for the delivery and pickup route scheduling of medical
surgical supplies under stochastic conditions. The developed technique was applied to a business operation case study in which
it was necessary to perform deliveries within specific time windows under variable transportation and service time conditions.
Materials and methods: The developed method comprises a deterministic solution and a stochastic solution, both of which are
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 with each other but also the best of them with the current procedure employed by the
company under study. Results and discussion: The indicators evaluated for all the variation coefficients show that the simheuristic
outperformed both the deterministic approach and the procedure used by the company. Conclusion: The implementation of the
simheuristic in the routing problem is a feasible alternative that satisfies the stochastic conditions.