3 research outputs found

    4th Party Logistics Problem Optimizer

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    This thesis considers a pickup and delivery problem with multiple time windows, a complex cost structure and factory constraints. We formulated the problem as a mathematical model and created an instance generator based on real data. We also implemented a heuristic solution method for the problem and ran extensive statistical tests. The mathematical model shows the complexity of the problem and is implemented in AMPL to give a benchmark for the proposed solution method. The instance generator was created based on real anonymized data from a 4th party logistics (4PL) company. The proposed solution method, called the 4th Party Logis- tics Optimizer, is a meta-heuristic approach with industry specific implementations. The solution method is refined through extensive statistical experiments. The ex- periments determine which parts of the solution method have a significant positive impact on the objective value. This leads to a final composition of our solution method. The final solution method is robustly giving near optimal solutions to re- alistic sized instances in seconds, and is a powerful tool for companies facing the proposed adaptation of the pickup and delivery problem.Masteroppgave i informatikkINF399MAMN-PROGMAMN-IN

    4th Party Logistics Problem Optimizer

    Get PDF
    This thesis considers a pickup and delivery problem with multiple time windows, a complex cost structure and factory constraints. We formulated the problem as a mathematical model and created an instance generator based on real data. We also implemented a heuristic solution method for the problem and ran extensive statistical tests. The mathematical model shows the complexity of the problem and is implemented in AMPL to give a benchmark for the proposed solution method. The instance generator was created based on real anonymized data from a 4th party logistics (4PL) company. The proposed solution method, called the 4th Party Logis- tics Optimizer, is a meta-heuristic approach with industry specific implementations. The solution method is refined through extensive statistical experiments. The ex- periments determine which parts of the solution method have a significant positive impact on the objective value. This leads to a final composition of our solution method. The final solution method is robustly giving near optimal solutions to re- alistic sized instances in seconds, and is a powerful tool for companies facing the proposed adaptation of the pickup and delivery problem

    Solving a pickup and delivery routing problem for fourth-party logistics providers

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    This paper studies a pickup and delivery routing problem for fourth-party logistics providers. The problem aims to schedule routes of vehicles to pick up orders from suppliers and deliver them to factory locations considering multiple time windows at suppliers and factory locations, a non-conventional cost structure, and certain factory dock constraints. We formulate the problem as a mathematical model and develop an efficient algorithm based on the adaptive large neighborhood search to solve the problem. The algorithm incorporates several heuristics to efficiently explore the search space for optimal solutions. The algorithm is refined through extensive statistical experiments to optimize the performances of the heuristics and to tune the parameters of the algorithm. The mathematical model and algorithm are evaluated on several problem instances based on a real case study in Europe. The numerical results demonstrate that the solution algorithm consistently obtains near-optimal solutions to real-sized problem instances.publishedVersio
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