Assessment of empty container repositioning policies in maritime transport

Purpose - Empty container repositioning is an important issue in the liner shipping industry. Generally stated, two groups of mathematical models have been proposed to tackle this issue. The first group aims to derive time-dependent origin-destination matrices that specify the number of empty containers to be repositioned at a decision epoch; the second group aims to develop effective state-feedback control policies consisting of dynamic decision-making rules. There is, however, a lack of research into the comparison of these two groups, especially with regard to realistic cases subject to uncertainties. The purpose of this paper is to evaluate and compare the performances of some typical repositioning policies from these two groups and to shed light on their relative merits and suitability in various realistic scenarios. Design/methodology/approach - Based on a literature review, the paper classifies the current empty container repositioning policies into two categories: origin-destination (OD) based solutions and state-based dynamic rules. Typical policies are selected from these two categories and then evaluated using a simulation tool. A range of scenarios are designed based on realistic cases considering the stochastic and dynamic nature of liner services. A comprehensive set of simulation experiments are conducted and analysed; and the relative merits and suitability of the repositioning policies are identified. Findings - Through a carefully designed comparative study, several research findings are obtained with regard to how the performances of different types of empty container repositioning policies are affected by various factors such as structure of service route, uncertainty of daily demands, and parametric optimisation methods. Originality/value - The study makes a good attempt to analyse the suitability of different empty container repositioning policies in different scenarios. This is an area that has lacked investigation. The research findings can help shipping companies and other relevant stakeholders better understand the relative merits of different empty container repositioning policies and better tackle the challenges in operating the container shipping system.