Containership routing with time deadlines and simultaneous deliveries and pick-ups Matthew G. Karlaftis a,1 , Konstantinos Kepaptsoglou a, * , Evangelos Sambracos b,2 a Department of Transportation Planning and Engineering, School of Civil Engineering, National Technical University of Athens, 5, Iroon Polytechniou Street, 15773 Zografou Campus, Greece b Department of Maritime Studies, University of Piraeus, 40, Karaoli and Dimitriou Street, 18534 Piraeus, Greece article info Article history: Received 17 November 2007 Received in revised form 12 May 2008 Accepted 13 May 2008 Keywords: Ship routing Containerships Pick-ups and deliveries Time deadlines abstract In this paper we seek to determine optimal routes for a containership fleet performing pick-ups and deliveries between a hub and several spoke ports. A capacitated vehicle rout- ing problem with pick-ups, deliveries and time deadlines is formulated and solved using a hybrid genetic algorithm for establishing routes for a dedicated containership fleet. Results on the performance of the algorithm and the feasibility of the approach show that a rela- tively small fleet of containerships could provide efficient services within deadlines. More- over, through sensitivity analysis we discuss performance robustness and consistency of the developed algorithm under a variety of problem settings and parameters values. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction In this paper we investigate route scheduling for a homogeneous fleet of containerships performing short-distance pick- ups and deliveries between hub-and-spoke ports, under time deadline constraints. Our motive stems from the real problem faced in transporting goods between the islands of the Aegean Archipelago and the main ports of the Greek mainland. Goods are transported to and from the Aegean islands mostly by trucks embarking Ro–Ro type passenger liners. These operations have proven to be problematic due to delays in passenger liners caused by disembarkation of trucks, minimal productivity of trucks while embarked on liners, insufficient liner capacity and the high cost of transportation (Sambracos, 2000a). As an alternative for transporting goods in the Aegean Archipelago, Sambracos (2000a) and Sambracos et al. (2004) proposed the use of a dedicated containership fleet carrying goods in small containers to islands under a predefined schedule. This service would alleviate most shortcomings since freight transport would be disengaged from passenger liners. Moreover, small containers would allow easier handling and efficient transportation between smaller ports and markets requiring les- ser quantities of goods (Sambracos, 2000b), thus reducing associated transport costs. We extend previous work by examining the applicability and results of a (metaheuristics) algorithm for routing with time deadlines and simultaneous deliveries and pick-ups in the context of scheduling a containership service. 1366-5545/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.tre.2008.05.001 * Corresponding author. Tel.: +30 210 7723167; fax: +30 210 7721424. E-mail addresses: mgk@central.ntua.gr (M.G. Karlaftis), kkepap@central.ntua.gr (K. Kepaptsoglou), sambra@unipi.gr (E. Sambracos). 1 Tel.: +30 210 7721280; fax: +30 210 7721424. 2 Tel.: +30 210 4142529; fax: +30 210 4142328. Transportation Research Part E 45 (2009) 210–221 Contents lists available at ScienceDirect Transportation Research Part E journal homepage: www.elsevier.com/locate/tre