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  • Integrated Planning in Hybrid Courier Operations

    Ninikas, G., Athanasopoulos, T., Zeimpekis, V., Minis, I.

    International Journal of Logistics Management (IJLM), 2013

    Abstract

    Purpose - We present the design and evaluation of an integrated system that supports planners and dispatchers to deliver enhanced courier operations. In addition to regular deliveries and pickups, these operations include: a) Mass deliveries to be served over a horizon of multiple days, and b) real-time dynamic requests to be served within the same service period.
    Design/methodology/approach – To address the aforementioned challenges, we developed an architecture that enhances a typical fleet management system by integrating purpose designed methods. Specifically, we plan mass deliveries taking into account typical routes of everyday operations. For planning dynamic requests in real time, we propose an efficient insertion heuristic.
    Findings – The results from testing the proposed optimization algorithms for planning mass deliveries and real-time dynamic requests are encouraging, since the proposed algorithms outperform current practices. Testing in a practical courier environment, indicated that the enhanced planning system may improve significantly operational performance
    Research limitations/implications – The proposed optimization algorithm for the dynamic aspect of this problem comprises a heuristic approach that reaches suboptimal solutions of high quality. The development of fast optimal algorithms for solving these very interesting and practical problems is a promising area for further research.
    Practical implications - The proposed integrated system addresses significant problems of hybrid courier operations in an integrated, balanced manner. Our tests showed that the allocation of flexible orders within a three-day time horizon improved the cost per flexible order by 7,4%, while computerized routing improved the cost of initial (static) routing by 14%. Furthermore, the proposed method for managing dynamic requests reduced the excess cost per served request by over 40%. Overall, the proposed integrated system improved the total routing costs by 16,5% on average compared to current practices.
    Originality/value – Both the planning problems and the related solution heuristics address original aspects of practical courier operations. Furthermore, the system integration and the proposed systematic planning contribute to the originality of the work.
    Keywords: Express logistics, fleet management systems, re-planning in vehicle routing, multi-period vehicle routing
    Paper type Research paper

    Post date: Wednesday, January 22, 2014 - 10:34
  • Lab Report, 2012-09

    Technical Report, Replanning in Vehicle Routing with Dynamic Pickups


    G. Ninikas, I. Minis


     

    Post date: Tuesday, November 19, 2013 - 09:43
  • Lab Report, 2013 - 07

    DeOPSys lab presentation in the Supply Chain & Logistics magazine (text in Greek)

    Supply Chain & Logistics Magazine - Τεύχος 57, 15 August - 01October 2013

    Post date: Tuesday, November 19, 2013 - 09:07
  • DeOPSys lab presentation in the Supply Chain & Logistics magazine

    Supply Chain & Logistics Magazine - Issue 57, 15 August - 01 October 2013

    Post date: Monday, November 18, 2013 - 13:08
  • Lab Report, 2013-06

    Scheduled Paratransit Transport Systems

    G. Dikas, I. Minis

    In this report we focus on ways to provide individualized services to people with mobility challenges using existing modes of public transport. We study the design of an interesting case, in which a bus operating in a public transport route may diverge from its nominal path to pick-up passengers with limited mobility and drop them off at their destination. We have modeled the design problem by a mixed integer-linear program, and we developed an exact Branch and Price approach to solve it to optimality. The proposed approach includes a labeling algorithm in which we introduced appropriate dominance rules to guarantee optimality. We have compared the efficiency of our approach with that of related algorithms from the literature. Furthermore, we have used the proposed approach to study key aspects of the system design problem, such as the effect of various constraints on the service level, and the tuning of the system’s parameters to address different transport environments.

    Post date: Wednesday, September 4, 2013 - 15:55