An adaptive guidance meta-heuristic for the vehicle routing problem with splits and clustered backhauls

Abstract

This paper presents the case study of an Italian carrier, Grendi Trasporti Marittimi, which provides freight transportation services by trucks and containers. Its trucks deliver container loads from a port to import customers and collect container loads from export customers to the same port. In this case study, all import customers in a route must be serviced before all export customers, each customer can be visited more than once and containers are never unloaded or reloaded from the truck chassis along any route. We model the problem using an Integer Linear Programming formulation and propose an Adaptive Guidance metaheuristic. Our extensive computational experiments show that the adaptive guidance algorithm is capable of determining good-quality solutions in many instances of practical or potential interest for the carrier within 10 min of computing time, whereas the mathematical formulation often fails to provide the first feasible solution within 3 h of computing time

A multiperiod drayage problem with customer-dependent service periods

“…A The node-arc model by [20] The model by [20] was proposed to address the single-period version of the drayage problem considered in this paper. That model assumes that all importers must be served before all exporters in any route, an assumption that can be relaxed (albeit at a cost) in the model discussed in this paper.…”

“…Thus, according to our experiments the (SEAF ) formulation is largely the preferable one. This is even more striking when it is compared with the flow-based compact formulation proposed in [20] for the single-period problem; in order not to move the focus away from our multi-period setting that formulation is recalled in A, and the comparison on single-period instances is reported in B.…”

“…These three approaches are extensively tested on several instances, in order to point out to what extent they can be adopted. The experiments show that the arc-flow formulation is by far the best performing, not only among the three but also against the closest formulation in the field, which was proposed by [20] for single-period problems. The effectiveness of the formulation allows us to thoroughly explore the connection between flexibility and routing costs, i.e., which savings can be obtained if customers accept extending the number of periods in which the transportation service is provided.…”

A set-covering formulation for a drayage problem with single and double container loads

“…As a result, our drayage problem is more difficult to solve owing to its combinatorial characteristics: a truck with a single container moves one loaded or one empty container, whereas a truck with two containers moves two loaded containers or two empty containers or one loaded container and one empty container. The distribution of more-than-one container per truck by different types of vehicles has received attention only very recently [e.g., Zhang et al (2015); Vidovic et al (2017)], and only Lai et al (2013Lai et al ( , 2015 and Funke and Kopfer (2016) investigated both multiple containers per truck and stay-with operations. 2.…”

“…Unlike Lai et al (2015), they assumed to have two types of trucks, which differ in terms transportation capacity and routing costs per unitary distance.…”