Browsing by Author "Hsu, Hsi-Mei"

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A GA methodology for the scheduling of yarn-dyed textile production
(2009-12-01)
Hsu, Hsi-Mei
;
Hsiung, Yai
;
Chen, Ying-Zhi
;
Wu, Muh-Cherng
;
工業工程與管理學系
This paper presents a scheduling approach for yarn-dyed textile manufacturing. The scheduling problem is distinct in having four characteristics: multi-stage production, sequence-dependent setup times, hierarchical product structure, and group-delivery (a group of jobs pertaining to a particular customer order must be delivered together), which are seldom addressed as a whole in literature. The scheduling objective is to minimize the total tardiness of customer orders. The problem is formulated as a mixed integer programming (MIP) model, which is computationally extensive. To reduce the problem complexity, we decomposed the scheduling problem into a sequence of sub-problems. Each sub-problem is solved by a genetic algorithm (CA), and an iteration of solving the whole sequence of sub-problems is repeated until a satisfactory Solution has been obtained. Numerical experiment results indicated that the proposed approach significantly outperforms the EDD (earliest due date) scheduling method-currently used in the yarn-dyed textile industry. (C) 2009 Elsevier Ltd. All rights reserved.
Equilibrium pricing and lead time decisions in a competitive industry
(2012-10-01)
Hong, I-Hsuan
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Hsu, Hsi-Mei
;
Wu, Yi-Mu
;
Yeh, Chun-Shao
;
工業工程與管理學系
Pricing and lead time are two crucial decisions to a success in today's competitive markets. This paper examines the equilibrium pricing and lead time decisions in a duopoly industry consisting of two large and several smaller firms with competition. We solve the sufficient Karush-Kuhn-Tucker (KKT) optimality conditions for the Nash equilibrium solution. We characterize the existence and uniqueness of the Nash equilibrium solution of pricing and lead time decisions for both homogenous and heterogeneous firms. Our case study provides important managerial insights about firms' behavior under price and lead time competition in a semiconductor manufacturing industry. (c) 2012 Elsevier B.V. All rights reserved.
Multiple lot-sizing decisions with an interrupted geometric yield and variable production time
(2009-10-01)
Hsu, Hsi-Mei
;
Su, Tai-Sheng
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Wu, Muh-Cherng
;
Huang, Liang-Chuan
;
工業工程與管理學系
This study examines a multiple lot-sizing problem for a single-stage production system with an interrupted geometric distribution, which is distinguished in involving variable production lead-time. In a finite number of setups, this study determined the optimal lot-size for each period that minimizes total expected cost. The following cost items are considered in optimum lot-sizing decisions: setup cost, variable production cost, inventory holding cost, and shortage cost. A dynamic programming model is formulated in which the duration between current time and due date is a stage variable, and remaining demand and work-in-process status are state variables. This study then presents an algorithm for solving the dynamic programming problem. Additionally, this study examines how total expected costs of optimal lot-sizing decisions vary when parameters are changed. Numerical results show that the optimum lot-size as a function of demand is not always monotonic. (C) 2009 Elsevier Ltd. All rights reserved.
PRICING DECISION AND LEAD TIME SETTING IN A DUOPOLY SEMICONDUCTOR INDUSTRY
(2008)
Hong, I-Hsuan
;
Hsu, Hsi-Mei
;
Wu, Yi-Mu
;
Yeh, Chun-Shao
;
工業工程與管理學系
Pricing and lead time setting are two important decisions in semiconductor foundry industries. This research considers the competition of a duopoly market consisting of two make-to-order firms in semiconductor foundry industries and presents a model to determine the equilibrium price and lead time of these two competing firms where each firm maximizes its own revenue and is subject to its own constraints in a duopoly market. In the model, customer mean demand rates of two competing firms are assumed as functions of committed lead times and prices provided by these two firms and the market. Furthermore, this paper utilizes a simulated procedure to verify the equilibrium price and lead time obtained by the analytical model presented in this paper.