OPTIMIZING READY-MIXED CONCRETE TRANSPORTATION BY A TRUCK MIXER ROUTING MODEL FOR CONCRETE PLANTS

This study aims to develop a truck mixer routing model to increase the efficiency of concrete delivery operations in concrete plants and to propose suitable solution methods for the model. In this study, a mixed-integer linear programming model was developed, based on a variant of the vehicle routing problem known as the capacitated vehicle routing problem with time windows, by incorporating constraints specific to concrete transportation. The objective of the model is to reduce transportation costs by minimizing the total distance travelled by truck mixers and the total number of truck mixers used. The model was first addressed by exact solution methods in Gurobi Optimizer. Since the vehicle routing problem is classified as an NP-hard problem, the complexity of the model increases with the number of customers, leading to a longer computation time. Thus, the model was addressed by a heuristic method developed for this study. The results show that the Gurobi Optimizer provided optimal solutions for up to 15 customers and 15 vehicles within a reasonable computation time, whereas the heuristic method quickly provided near-optimal solutions with a 3.39% cost increase on average.