Vehicle Routing Problem with Deadline and Stochastic Service Times: Case of the Ice Cream Industry in Santiago City of Chile

Sebastián Dávila,Guillermo Fuertes,Manuel Vargas,Mauricio Camargo,Miguel Alfaro

doi:10.3390/math9212750

Sebastián Dávila, Guillermo Fuertes + Show 3 more

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https://doi.org/10.3390/math9212750

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Abstract

The research evaluates the vehicular routing problem for distributing refrigerated products. The mathematical model corresponds to the vehicle routing problem with hard time windows and a stochastic service time (VRPTW-ST) model applied in Santiago de Chile. For model optimization, we used tabu search, chaotic search and general algebraic modeling. The model’s objective function is to minimize the total distance traveled and the number of vehicles using stochastic waiting restrictions at the customers’ facilities. The experiments were implemented in ten scenarios by modifying the number of customers. Experiments were established with several customers that can be solved using the general algebraic modeling technique in order to validate the tabu search and the chaotic search methods. The study considered two algorithms modified with Monte Carlo (tabu search and chaotic search). Additionally, two modified algorithms, TSv2 and CSv2, were proposed to reduce execution time. These algorithms were modified by delaying the Monte Carlo procedure until the first set of sub-optimal routes were found. The results validate the metaheuristic chaotic search to solve the VRPTW-ST. The chaotic search method obtained a superior performance than the tabu search method when solving a real problem in a large city. Finally, the experiments demonstrated a direct relationship between the percentage of customers with stochastic waiting time and the model resolution time.

Highlights

The cold chain is the key element in the transport and logistics of perishables
The investigation corresponds to the resolution of a real vehicle routing problem with time windows (VRPTW)-service times (ST) product transport problem in the City of Santiago
The results validated the use of chaotic search (CS) for VRPTW-ST, and the resolution capacity of the CS algorithm for problems with stochastic time-out variables was established

Summary

Introduction

The cold chain is the key element in the transport and logistics of perishables. The cold chain consists of steps that are part of the refrigeration and freezing process that perishable products need in order to reach their final consumer in optimal conditions [1]. Food products often go bad due to long travel times and frequent stops to serve customers during the delivery process. It is difficult to effectively manage cold chain distribution and ensure maximum freshness [2]. Logistics operators must have vehicles with temperature control, which are generally more expensive and consume more fuel than normal vehicles. The late delivery of perishable food significantly affects the costs of the logistics operator and retailers [3,4]

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