Student：Chen, Hsu-Hsing
Thesis Advisor： Professor Yang, Feng-Cheng
Thesis Topic：
Mathematical Programming and Metaheuristics for the Material Handling Network Scheduling Problem
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論文摘要：
Modern factories heavily depend on Automated Material Handling Systems (AMHSs) for internal logistics. As material handling networks grow in complexity, effective coordination among AMHSs becomes more crucial. This research addresses the scheduling problem in this context by defining the Material Handling Network Scheduling Problem (MHNSP), with the goal of minimizing the makespan for transportation jobs. Some key contributions include considering path flexibility for transportation jobs and modeling local buffer capacity limits.
We propose three models to solve the MHNSP: a Constraint Programming (CP) model, an Integer Programming (IP) model, and a Metaheuristic model. Some highlights of the proposed models are 1) the CP model employs a hierarchical structure to model the constraints, 2) the IP model addresses buffer constraints by identifying operation overlaps using pairwise relationships, and 3) the Metaheuristic model utilizes a discrete-event-based decoding procedure to determine the start time of each operation.
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The models are evaluated through four numerical tests. First, Metaheuristic parameters are optimized using the Taguchi method. Performance is then compared across 360 randomly generated test problems. Results indicate that the IP model performs well for small problems, while the CP and Metaheuristic models are more effective for larger problems. It also shows that increasing path flexibility can reduce makespan by an average of 13% in large-scale problems. The CP and Metaheuristic models are also compared in extra-large problems. In this test, CP model consistently provides better solutions than the Metaheuristic model given sufficient solving time, demonstrating the potential of CP in real applications. Finally, the identical request test highlighted that optimal path selection could lead to a 35.7% reduction in makespan by balancing node workloads and minimizing time spent at transfer sites.
In summary, this research highlights the critical role of path flexibility and operation sequencing in optimizing material handling networks.
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論文海報：
