GRASP with Hybrid Path Relinking for Bi-Objective Winner Determination in Combinatorial Transportation Auctions

The procurement of transportation services via large-scale combinatorial auctions involves a couple of complex decisions whose outcome highly influences the performance of the tender process. This paper examines the shipper's task of selecting a subset of the submitted bids which efficiently trades off total procurement cost against expected carrier performance. To solve this bi-objective winner determination problem, we propose a Pareto-based greedy randomized adaptive search procedure (GRASP). As a post-optimizer we use a path relinking procedure which is hybridized with branch-and-bound. Several variants of this algorithm are evaluated by means of artificial test instances which comply with important real-world characteristics. The two best variants prove superior to a previously published Pareto-based evolutionary algorithm.

On Transport Service Selection in Intermodal Rail/Road Distribution Networks

Intermodal rail/road freight transport constitutes an alternative to long-haul road transport for the distribution of large volumes of goods. The paper introduces the intermodal transportation problem for the tactical planning of mode and service selection. In rail mode, shippers either book train capacity on a per-unit basis or charter block trains completely. Road mode is used for short-distance haulage to intermodal terminals and for direct shipments to customers. We analyze the competition of road and intermodal transportation with regard to freight consolidation and service cost on a model basis. The approach is applied to a distribution system of an industrial company serving customers in eastern Europe. The case study investigates the impact of transport cost and consolidation on the optimal modal split.

Contribution to the Energy Efficiency and Environmental Compatibility of Cranes for Inland Waterway/ Feeder Ship Handling

Basis for the economic efficiency of international supply chains rests on the efficiency of multimodal transport chains. Materials and products are transported along the edges of transport networks with the forwarder endeavouring to maximize the transport efficiency by using the effects of scale along the edges. The network nodes provide the means to have the goods transferred between the means of transport. Whilst purely economic criteria were initially the driving force for a change in the means of transport, ecological requirements are now becoming ever more relevant. The transportation chains should not only be economically presentable but also it makes sense for them to have a “green footprint”. In this context the following considerations will deal with the transfer processes within the network nodes, especially those within inland and feeder terminals. Replies are to be given to the questions as to how far the choice of the crane primary drive has an impact on energy consumption and environmental compatibility of handling the goods and which additional benefit does the recuperation of engrained energies bring during the handling process.