A Multi-Agent Approach to the Multi-Echelon Capacitated Vehicle Routing Problem

The paper presents a concept and application of a multi-agent approach to modeling and optimization the Multi-Echelon Capacitated Vehicle Routing Problem. Two environments (mathematical programming (MP) and constraint logic programming (CLP)) and two types of agents were integrated. The strengths of MP and CLP, in which constraints are treated in a different way and different methods are implemented, were combined to use the strengths of both. The proposed approach is particularly important for the decision models with an objective function and many discrete decision variables added up in multiple constraints. The Two-Echelon Capacitated Vehicle Routing Problem (2E-CVRP) is an extension of the classical Capacitated Vehicle Routing Problem (CVRP) where the delivery depot-customers pass through intermediate depots (called satellites). Multi-echelon distribution systems are quite common in supply-chain and logistic systems. The presented multi-agent approach will be compared with classical mathematical programming on the same data sets.