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  • A Web-Tool for Planning Environmental Friendly Freight Combined Transport Pperations

    Zeimpekis, V., Mamasis, K. and Minis I. 


    Procedia Social and Behavioral Sciences, Transport Research Arena – Europe 2012, vol. 48, 2012, 464-472.


    Abstract


    Recent EU transportation sector actions focus towards the development of integrated, technology-based transportation systems to support co-modality operations. These may contribute significantly towards the minimization of operational costs and improvement of customer satisfaction, while being energy efficient and environmental friendly. This paper presents the design, implementation and pilot testing of an innovative web tool that helps shippers and freight forwarders in seeking near optimal combined transport solutions taking into account trip costs, transportation durations, risk and CO2 emissions. The paper analyses the architecture of the platform, which is based on user requirements, as mapped through an extensive elicitation process. Subsequently, it describes the methods used to:  a) generate transportation routes using available data and related OR techniques, b) request offers from registered providers, and c) monitor delivery. Finally, the paper presents results from pilot testing of the platform in actual cases from five EU countries.

    Post date: Monday, July 23, 2012 - 10:09
  • Lab Report, 2012-05

    Zeimpekis, V., Mamasis, K., Minis, I.


    A Web-Tool for Planning Environmental Friendly Freight Combined Transport Opertation


    In the Proceedings of the Transport Research Arean-Europe 2012, Athens, Greece, 23-26 April, 2012


     

    Post date: Friday, April 27, 2012 - 10:36
  • Lab Report, 2012-04

    Mamasis, K., Minis, I., Dikas, G.


    Managing Vehicle Breakdown Incdents During Urban Distribution Product


    Accepted for publication in JORS, 2012


    Abstract


    This paper addresses a case in which a vehicle, member of a fleet distributing a common single product, is immobilized permanently while executing its distribution plan. The other, active, vehicles of the fleet are then rerouted to serve the remaining non-served clients. We model this re-planning problem as a variation of the Team Orienteering Problem constraining all vehicle routes to an upper time, or distance, limit and taking into account the limited capacity of the fleet vehicles. We propose an efficient heuristic to provide solutions in almost real-time. The heuristic progressively constructs new routes for each active vehicle taking into account that a vehicle may replenish its load by visiting the warehouse or the immobilized vehicle. We solve the replenishment sub-problem by developing a fast labelling algorithm. To test the effectiveness of the proposed heuristic, we have developed a Genetic Algorithm (GA) that obtains high quality (but computationally expensive) solutions and compare them to those obtained by the heuristic.
    Keywords: Team Orienteering Problem, Urban Distribution, Distribution Vehicle Breakdown, Vehicle Routing, City Logistics
     

    Post date: Friday, April 27, 2012 - 10:30
  • Lab Report, 2012-03

    Gliatis, V., Minis, I.


    Assessing the Impact fo Failures in Service Operations Using Experimntal Design with Simulation


    Accepted for publication in International Journal of Quality & Reliability Management, 2012


    Abstract
    Purpose – Failures represent an important source of variability in service operations and a major performance challenge. As a consequence, the effective management of failures is a prerequisite to achieve lean services. In this paper we focus on the operational perspective of failures; that is we attempt to quantify the impact of critical failure parameters on key system performance measures, such as cycle time and work-in-process. We also analyze various operational concepts, or management practices, that service organizations use to address the effects of failures.
    Design/methodology/approach – We use discrete event simulation to model the behavior of a typical two-stage service system (front-office, back-office), and design of experiments to estimate the impact of significant parameters that characterize service failures, on key system performance measures. In a final experiment we analyze three of the most common practices used by management to address failures, and the impact of these practices on system performance under different conditions. The findings are validated through a case study in the post trade financial services.
    Findings – The results of this study suggest that failures and rework degrade the performance of service systems. This adverse impact is reinforced, if specific inputs of the system deteriorate, such as the ability of the service organization to deliver appropriate quality, to detect failures early and to be capable enough to recover timely and efficiently from failures. In addition, the results show that typical management practices used to address the impact of failures have strengths and weaknesses depending on the characteristics of both the service system and the failures. If this is not taken into consideration, the above managerial practices may lead only to short-term improvements, while the main causes of failures will remain unsolved.
    Originality/value – Analyzing the impact of failures in a service environment is a challenging task. In this paper, we complement the existing literature on service failures by focusing on the related effects on operations. With the use of simulation, we quantify the impact of failures on key aspects of operations of the service system.  We also provide useful insight into the parameters that determine the effectiveness of various management practices used in practice to address failures. Finally, we use a case study in financial services to validate our results.
    Keywords: lean services, service failures, quality in service operations
    Paper type Research paper

    Post date: Friday, April 27, 2012 - 10:25
  • Lab Report, 2012-02

    Zeimpekis, V., Minis, I., Giaglis, G., Mamasis, K.


    Real-Time Fleet Management and Retouting in CIty Logistics


    Refereed Journal Article, accepted for publication in International Journal of Operation Research and Information Systems

    Post date: Friday, April 27, 2012 - 10:19