Browsing by Author "Huang, Jia-Yen"

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AN EFFICIENT HEURISTIC FOR TRANSPORT FLEET MAINTENANCE SCHEDULING IN A MAINTENANCE SYSTEM WITH LIMITED CAPACITY
(2014-10-01)
Yao, Ming-Jong
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Huang, Jia-Yen
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
In the real world, the managers of a transportation fleet need to carefully determine the maintenance cycles of vehicles so as to minimize the average total costs (including the operating costs and the maintenance costs). Furthermore, since the maintenance system is usually equipped with limited manpower and facilities, it has limited capacity to provide maintenance service for the transportation fleet. Therefore, we are motivated to determine the optimal maintenance cycle of vehicles and to generate a feasible maintenance schedule of a transport fleet in this study. To solve this problem, we first obtain candidate solutions by solving an unconstrained model using a search algorithm. Then, we test feasibility for each one of these candidate solutions. Finally, among these candidate solutions, we pick the \'best\' solution that secures a feasible maintenance schedule with the minimum average costs. Based on our random experiments, we demonstrate that the proposed search algorithm could effectively solve the Transportation Fleet Maintenance Scheduling Problem in a maintenance system with limited capacity.
On the optimal lot-sizing and scheduling problem in serial-type supply chain system using a time-varying lot-sizing policy
(2013-02-01)
Huang, Jia-Yen
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Yao, Ming-Jong
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運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
In this paper, we solve the optimal sequencing, lot-sizing and scheduling decisions for several products manufactured through several firms in a serial-type supply chain so as to minimise the sum of setup and inventory holding costs while meeting given demand from customers. We propose a three-phase heuristic to solve this NP-hard problem using a time-varying lot- sizing approach. First, based on the theoretical results, we obtain candidate sets of the production frequencies and cycle time using a junction-point heuristic. Next, we determine the production sequences for each firm using a bin-packing method. Finally, we obtain the production times of the products for each firm in the supply chain system by iteratively solving a set of linear simultaneous equations which were derived from the constraints. Then, we choose the best solution among the candidate solutions. Based on the numerical experiments, we show that the proposed three-phase heuristic efficiently obtains feasible solutions with excellent quality which is much better than the upper-bound solutions from the common cycle approach.
Optimal lot-sizing and joint replenishment strategy under a piecewise linear warehousing cost structure
(2017-03)
Yao, Ming-Jong
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Huang, Jia-Yen
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交大名義發表
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National Chiao Tung University
In the general lot-sizing replenishment problem, warehousing costs are considered as part of the inventory holding cost. When decision makers need warehouse space to store their products, they generally think about the warehousing cost as included in the inventory cost. In this study, we investigate an optimal lot-sizing and replenishment problem under a piecewise linear warehousing cost structure. Theoretical analysis of the optimality structure of a model of multiple stock-keeping units with joint inventory costs is conducted, and an effective search algorithm is proposed. Based on our random experiments, we demonstrate that our search algorithm outperforms the approach that the existing literature offers as solution.
Optimal lot-sizing and joint replenishment strategy under a piecewise linear warehousing cost structure
(2017-03-01)
Yao, Ming-Jong
;
Huang, Jia-Yen
;
交大名義發表
;
National Chiao Tung University
In the general lot-sizing replenishment problem, warehousing costs are considered as part of the inventory holding cost. When decision makers need warehouse space to store their products, they generally think about the warehousing cost as included in the inventory cost. In this study, we investigate an optimal lot-sizing and replenishment problem under a piecewise linear warehousing cost structure. Theoretical analysis of the optimality structure of a model of multiple stock-keeping units with joint inventory costs is conducted, and an effective search algorithm is proposed. Based on our random experiments, we demonstrate that our search algorithm outperforms the approach that the existing literature offers as solution.
Scheduling of transportation fleet maintenance service by an improved Lipschitz optimization algorithm
(2014-05-04)
Yao, Ming-Jong
;
Huang, Jia-Yen
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
This study proposes a new and improved Lipschitz optimization algorithm to obtain an E-optimal solution for solving the transportation fleet maintenance-scheduling problem. It employs a procedure based on slope-checking and step-size comparison mechanisms to improve the computational efficiency of the Evtushenko algorithm. Our numerical experiments used 36,000 randomly generated instances to compare the run time and solution quality of our proposed algorithm with the alternative approach in the literature. Our results indicate that the run time of the proposed algorithm could be significantly improved by more than 80% in over 50% of instances in our numerical experiments. We conclude that our proposed algorithm significantly improves the computational efficiency of the conventional Evtushenko algorithm.