An optimization model for the distribution of perishable products with consideration of road roughness conditions

In this article, we discuss a vehicle routing problem with time windows (VRPTW) for the transport of perishable products with considera-‎tion of road roughness constraints. The proposed model includes simultaneous pickup and delivery operations. Unlike almost all previous ‎studies, which mainly consider travel distance and temperature as factors in product deterioration, we take into account the roughness condi-‎tions of the roads in order to preserve their quality during transport. The objective is therefore to satisfy a set of customers, while respecting ‎the constraints related to multi-product transport, simultaneous pickup and delivery operations, time windows and roughness conditions of ‎the roads. We express the problem in the form of a mixed linear integer program. The model is solved with CPLEX's traditional Branch & ‎Cut (B&C) and a two-phase decomposition heuristic (TPDH). The test results show that TPDH produces satisfactory solutions in a short ‎time for all instances studied, with an average time of 290,19 seconds compared to 2941,61 seconds for B&C. In addition, TPDH has an ‎average deviation of +18,3 % from the total cost of the objective compared to B&C, making it a relevant option for applications that require ‎fast computation.