A Multi-Compartment Vehicle Routing Problem with Loading and Unloading Costs

Abstract

This paper discusses a multi-compartment vehicle routing problem (MCVRP) that occurs in the context of grocery distribution. Different temperature-specific product segments (e.g., frozen or ambient) are transported from a retail warehouse to outlets. Different temperature-specific product segments can be transported together using multi-compartment vehicles. These trucks are technically able to have different temperature zones on the same truck by separating the capacity of a vehicle flexibly into a limited number of compartments. On one hand, this leads to a cost saving as different product segments ordered by one outlet can be delivered jointly using only one truck. This impacts the routing and the number of stops—i.e., the transportation costs and unloading costs. On the other hand, more than one shipping gate has to be approached at the warehouse to collect and load different product segments. As a consequence, the number of segments on each truck and therefore the number of compartments impact loading, transportation, and unloading costs. An extended MCVRP with flexible compartments is presented to account for these loading and unloading costs. To solve the problem that arises, a large neighborhood search (LNS) tailored to the extended model is defined. The LNS includes problem-specific extensions in terms of the removal and reinsert operators as well as the termination criteria. It is tested using a case study with a retailer, benchmark data, and randomly generated data. Results are also compared to existing approaches. In line with the analyses performed for the model introduced, it is shown that the integration of loading and unloading costs into the model impacts routing considerably, and ultimately results in significant savings potential for retailers.