Browsing by Author "Lee, AHI"

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Analytic network process (ANP) approach for product mix planning in semiconductor fabricator
(2005-04-18)
Chung, SH
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Lee, AHI
;
Pearn, WL
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工業工程與管理學系
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Department of Industrial Engineering and Management
This paper proposes an application of the analytic network process (ANP) for the selection of product mix for efficient manufacturing in a semiconductor fabricator. In order to evaluate different product mixes, a hierarchical network model based on various factors and the interactions of factors is presented. By incorporating experts' opinion, a priority index can be calculated for each product mix studied, and a performance ranking of product mixes can be generated. The results provide guidance to a fab regarding strategies for accepting orders to maximize the manufacturing efficiency in considering the aspects of product, equipment efficiency and finance. The model can be easily understood and followed by administrators to determine the most efficient product mix for a fab. (c) 2004 Elsevier B.V. All rights reserved.
Job order releasing and throughput planning for multi-priority orders in wafer fabs
(2003-01-01)
Chung, SH
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Pearn, WL
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Lee, AHI
;
Ke, WT
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工業工程與管理學系
To meet the production target of multi-level (multiple priority rank) orders in wafer fabs, this paper uses a hierarchical framework based on a mathematical model, and without the assistance of any simulation tool, to build a production scheduling system to plan wafer lot releasing sequence and time. This system first applies capacity loading analysis to set up the batch policy for each level (rank) of orders. Next, the production cycle time of each product level is estimated with considerations of batching and loading factor. The cycle time is then used to derive system control parameters such as the most appropriate level of work in process (WIP) and the number of daily operations on the bottleneck workstation. Lastly, a Constant WIP mechanism is applied to establish a wafer release sequence table and a throughput timetable. The due date designation for each specific order can hence be confirmed. With the comparison with the result of simulation, it shows that under the designed system the performance and planning measures in the master production schedule can be drawn up quickly and accurately, and the system throughput target and due date satisfaction can be achieved. Overall, the proposed production scheduling system is both effective and practicable, and the planning results are supportive for good target planning and production activity control.
Product mix optimization for semiconductor manufacturing based on AHP and ANP analysis
(2005-06-01)
Chung, SH
;
Lee, AHI
;
Pearn, WL
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
In a competitive market, a company needs to utilize its available capacity efficiently in order to acquire high profit. The purpose of this paper is to present effective approaches to find a set of product mix optimal for the company to achieve the optimal manufacturing. Analytic hierarchy process ( AHP) and analytic network process ( ANP) approaches are taken to analyse multiple process inputs and outputs, incorporating experts' opinion on their priority of importance, to obtain optimal product mixes for semiconductor production. The results provide guidance to the fabricator regarding strategies for accepting orders to maximize the manufacturing efficiency and the profit, while simultaneously considering other important input and output factors for maintaining manufacturing smoothness.
Using constraint satisfaction approach to solve the capacity allocation problem for photolithography area
(2006)
Chung, SH
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Huang, CY
;
Lee, AHI
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This paper addresses the capacity allocation problem for photolithography area (CAPPA) under an advanced technology environment. The CAPPA problem has two characteristics: process window and machine dedication. Process window means that a wafer needs to be processed on machines that can satisfy its process capability (process specification). Machine dedication means that after the first critical layer of a wafer lot is being processed on a certain machine, subsequent critical layers of this lot must be processed on the same machine to ensure good quality of final products. A production plan, constructed without considering the above two characteristics, is difficult to execute and to achieve its production targets. Thus, we model the CAPPA problem as a constraint satisfaction problem (CSP), which uses an efficient search algorithm to obtain a feasible solution. Additionally, we propose an upper bound of load unbalance estimation to reduce the search space of CSP for searching an optimal solution. Experimental results show that the proposed model is useful in solving the CAPPA problem in an efficient way.