Browsing by Author "Chen, Wen-Chih"

Now showing 1 - 20 of 20

A case study to evaluate the productivity changes of the thermal power plants of the Taiwan power company
(2007-09-01)
Chien, Chen-Fu
;
Chen, Wen-Chih
;
Lo, Feng-Yu
;
Lin, Yi-Chiech
;
工業工程與管理學系
This paper developed an approach based on data envelopment analysis and Malmquist productivity index to investigate the performance of power plants and conducted an empirical study with eight thermal power plants in Taiwan. The analysis results show the productivity improvements, and thus, help Taiwan Power Company to monitor and diagnose changes in the productivity of its thermal power plants. Furthermore, this study also provides specific directions for improvements to increase competitiveness in the face of the continuing liberalization of the Taiwanese power generation market.
A DEA benchmarking methodology for new product development process optimization
(2007)
Trappey, Amy J. C.
;
Chiang, Tzu-An
;
Chen, Wen-Chih
;
Kuo, Jen-Yau
;
Yu, Chia-Wei
Developing new products on time within budget constraints is a crucial issue to survive in today\'s competitive marketplace. However, unpredictable incidents occur during new product development (NPD) processes, which often cause expenses, resources and schedule overruns. Traditional project management tools lack of efficient and effective methods to solve these problems and challenges. Hence, this study applies the data envelopment analysis (DEA) concept to develop a novel project planning and management decision support methodology for NPD that can optimally allocate resources and dynamically response to unexpected delays and budget overruns. The research adopts the methodology to a mobile phone NPD project case to demonstrate the method\'s real-world application and illustrate the effectiveness of the proposed methodology in-depth.
A flexible web-based simulation game for production and logistics management courses
(2009-08-01)
Chang, Yung-Chia
;
Chen, Wen-Chih
;
Yang, Yung-Nien
;
Chao, Hui-Cheng
;
工業工程與管理學系
This study develops a flexible simulation game environment called SIMPLE (Simulation of Production and Logistics Environment) in order to raise teaching effectiveness and improve classroom teaching in emerging production paradigms. Instructors can tailor SIMPLE by simply setting the appropriate parameters. SIMPLE can thus be adopted at various teaching stages to teach different major business concepts, such as inventory management, capacity management, pricing determination and negotiation, and information-sharing between players. Meanwhile, SIMPLE was employed in two courses to evaluate the degree of students' acceptance of using SIMPLE in classrooms. The results also showed that SIMPLE was generally well received by students. (C) 2009 Elsevier B.V. All rights reserved.
A procedure for large-scale DEA computations
(2009-06-01)
Chen, Wen-Chih
;
Cho, Wei-Jen
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Data envelopment analysis (DEA), a performance evaluation method, measures the relative efficiency of a particular decision making unit (DMU) against a peer group. Most popular DEA models can be solved using standard linear programming (LP) techniques and therefore, in theory, are considered as computationally easy. However, in practice, the computational load cannot be neglected for large-scale-in terms of number of DMUs-problems. This study proposes an accelerating procedure that properly identifies a few "similar" critical DMUs to compute DMU efficiency scores in a given set. Simulation results demonstrate that the proposed procedure is suitable for solving large-scale BCC problems when the percentage of efficient DMUs is high. The computational benefits of this procedure are significant especially when the number of inputs and outputs is small, which are most widely reported in the literature and practices. (C) 2008 Elsevier Ltd. All rights reserved.
A trading decision support model to maximize the sustainability of a self-financed guaranteed farmgate price program
(2019-03-01)
Chen, Wen-Chih
;
Wu, Cheng-Hung
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
We study a non-government organization (NGO) program that supports the household livelihood of small farmers by committing to purchase a fixed quantity at a guaranteed farmgate price of a storable agri-product under price fluctuation. Since the World Trade Organization (WTO) disciplines its members to limit and reduce domestic support for the agriculture, storing and trading (selling) the product on the spot market at a favorable price generates revenue to cover the cost of the program. The objective of this study is to develop a stochastic dynamic trading decision model that maximizes the sustainability of the NGO's supporting program, measured as the survival probability, i.e. the probability that the program can continue operating after a predetermined period of time. The results of a numerical study, based on the tilapia aquaculture in Taiwan, show that our model yields higher survival probability (after 4 years) than the profit-maximization policy by close to 10% in average. Moreover, the trading decision optimization is particularly suitable for market environments with high price fluctuation, i.e. the most challenging circumstances for small farmers.
A unified model for detecting efficient and inefficient outliers in data envelopment analysis
(2010-02-01)
Chen, Wen-Chih
;
Johnson, Andrew L.
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Data envelopment analysis(DEA) uses extreme observations to identify superior performance, making it vulnerable to outliers. This paper develops a unified model to identify both efficient and inefficient outliers in DEA. Finding both types is important since many post analyses, after measuring efficiency, depend on the entire distribution of efficiency estimates. Thus, outliers that are distinguished by poor performance can significantly alter the results. Besides allowing the identification of outliers, the method described is consistent with a relaxed set of DEA axioms. Several examples demonstrate the need for identifying both efficient and inefficient outliers and the effectiveness of the proposed method. Applications of the model reveal that observations with low efficiency estimates are not necessarily outliers. In addition, a strategy to accelerate the computation is proposed that can apply to influential observation detection. (C) 2009 Elsevier Ltd. All rights reserved.
AN INDIRECT WORKFORCE (RE)ALLOCATION MODEL FOR SEMICONDUCTOR MANUFACTURING
(2008)
Chien, Chen-Fu
;
Chen, Wen-Chih
;
Hsu, Shao-Chung
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Semiconductor industry is a capital intensive and knowledge intensive industry, in which human resource management and human capital enhancement is increasingly important. To maintain competitive human resource, it is critical to develop a decision framework for headcount planning and workforce allocation for indirect labors. Motivated by the needs in real setting, this study aims to develop a model for allocating indirect workforce among semiconductor fabrication facilities to meet expected outputs and labor productivity improvement. Workforce allocation and reallocation based on the overall corporate workforce level is essential so that the shortage or exceed workforce will be balanced among different production sites. The key to achieve this purpose is the proper understanding of real requirements of each production site according to its corresponding tasks assigned. Non-parametric activity analysis approach is used for the workforce requirement estimation given delegated tasks. The estimation is based on the best performance from the past with adjustments reflecting the expected productivity growth.
Determining radial efficiency with a large data set by solving small-size linear programs
(2017-03-01)
Chen, Wen-Chih
;
Lai, Sheng-Yung
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This paper presents a new algorithm for determining radial efficiency with a large data set by using small-size linear programs (LPs). Instead of trying to "reduce" the size of individual LPs, the proposed algorithm attempts to "control" the size of individual LPs, e.g., no more than 100 data points each time while maintaining the solution quality. The algorithm is specifically designed to address the problem of LP size limitation. From the empirical results, we conclude that the proposed algorithm can converge within a reasonable number of iterations without incurring extra computation time and has savings of up to 60 % of the benchmarks when the data set contains 15,000 points.
ECONOMIC EFFICIENCY ANALYSIS OF WAFER FABRICATION FACILITIES
(2008)
Chen, Wen-Chih
;
Chien, Chen-Fu
;
Chou, Ming-Hsuan
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Semiconductor industry is capital intensive and competitive, and thus efficiently utilizing resources to provide products and services is essential for maintaining competitive advantages. Knowing whether the resource is properly utilized is the foundation for future improvements and/or decision making. This study investigates the economic efficiency of fabrication facility (fab) operations. We develop a two-stage overall efficiency model, which clearly defines and explains the "real" performance of fab production operations and the non-production issues. The model provides an overall performance index while considering different aspects. A single performance index can be used to evaluate and rank the performance for period review. Factors affecting performance can be identified. Furthermore, according to a real case, an ex post relative efficiency analysis is conducted and the initial results are reported. The case study can help providing diagnosis for inefficient production facilities and identifying best practices of efficient production units.
Evaluating capacity pooling strategy in semiconductor manufacturing: a productivity perspective study
(2011)
Chen, Wen-Chih
;
Chien, Chen-Fu
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Recently, increasing attention has been focusing on the concept of the borderless fab, which expands capacity through a manufacturing strategy rather than capital investments. In a borderless fab, the capacity of several wafer fabs is pooled, and partially completed wafers are allowed to move from one fab to another. This paper proposes a model to evaluate the potential benefits of adopting capacity pooling from the macro-viewpoint. We demonstrate our model using actual full-scale fab-level operational data, and the result reveals that capacity pooling can improve monthly capacity by 3% on average.
Fine pitch "NCF-type Compliant-bumped COG"
(2007)
An, Chao-Chyun
;
Chang, Shyh-Ming
;
Chen, Ming-Yao
;
Kao, Kuo-Shu
;
Tsang, Jimmy
Non-Conductive-Film (NCF) type of Chip-on-Glass (COG) bonding method ensures the micro-order direct bonding between the IC electrode and glass substrate electrode. The binding force of the applied adhesive achieves electrical connections between the bumps on the IC chip and the electrodes on the glass substrate. The mathematical calculation results of bump stress and bump deformation are used to identify the environmental temperature range for the given COG bonding structure. Both of the calculation and experimental results demonstrate the feasibility of using the compliant bumps to achieve a high compressive stress, high bump deformation and low as well as stable connection resistance at various environmental temperatures. The 1,000 hrs 85 degrees C/85%RH reliability test result will be indicated.
Large-scale Internet benchmarking: Technology and application in warehousing operations
(2010-04-01)
Johnson, Andy
;
Chen, Wen-Chih
;
McGinnis, Leon F.
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Effective benchmarking requires standards for measuring performance across a broad range of organizations. Industry-benchmarking measures the relative performance levels of similar operations, but gathering sufficient data to robustly characterize best performance is the primary hurdle to more widespread implementation. This paper describes the development of an innovative, large-scale benchmarking methodology which employs Internet technology to overcome the data collection problem. We discuss a particular instance of this approach, iDEAs-W-the result of an ongoing collaboration between academia and the warehousing industry. This paper's purpose is to demonstrate the methodology for the warehousing industry and share our insights to allow others to refine the tool for applications in other industries. (C) 2009 Elsevier B.V. All rights reserved.
Measuring relative performance of wafer fabrication operations: a case study
(2011-06-01)
Chen, Wen-Chih
;
Chien, Chen-Fu
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This paper was motivated by a request to review relative operations performance for various fabrication facilities within a leading Taiwanese semiconductor manufacturer. Performance evaluation is important but often controversial. To dispel the controversy, we propose a two-stage fabrication process model to systematically analyze metrics currently adopted, and show that the commonly used wafer-based indices are biased for operations performance. Instead, they should be decomposed into productivity, representing true operations performance, and manufacturability. We suggest the use of data envelopment analysis because of its confirmed linkages to other widely used productivity measures and its overall performance via relative comparisons. The case study illustrates how the two-stage model evaluates and analyzes real-world operations, and the empirical results show the drawbacks of conventional methods.
Measuring the performance of and tradeoffs within the triple bottom line
(2019-01-02)
Chen, Wen-Chih
;
Su, Che-Ping (Jack)
;
Rogers, Mary Margaret
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
In this article, we use the data of Organization for Economic Cooperation and Development (OECD) trucking industry to illustrate a new analysis framework based on data envelopment analysis (DEA) using the concept of the triple bottom line to show the internal tradeoffs among economic, environmental and social issues within individual Decision Making Unit (DMU). We evaluate the various efficiencies of each national trucking industry by comparing it to its peers and develop indices that allow us to investigate the internal tradeoffs among the three areas of the triple bottom line. These measures help us understand how each country can choose to emphasize certain inputs and outputs to increase efficiency. The framework can be extended to other applications.
Requirement estimation for indirect workforce allocation in semiconductor manufacturing
(2010)
Chien, Chen-Fu
;
Chen, Wen-Chih
;
Hsu, Shao-Chung
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This work, based on a real case, presents a model to estimate indirect workforce requirements of semiconductor fabrication facilities (fabs) so that the workforce can be fairly allocated. There is a concern in a real setting to fairly allocate the overall corporate workforce among the fabs, particularly when they compete in performance, and properly determining the actual requirement is the most critical in the decision process. The actual requirements of the workforce, especially the indirect workforce, for fabs may be indeterminate due to the lack of a well-defined workforce-output relationship. This paper presents a non-parametric frontier approach for estimating the indirect workforce, and the estimate is based on the best past performance adjusted to reflect the expected productivity growth. An empirical study was conducted in a leading foundry in Taiwan that has a number of 8-inch fabs. The proposed (re)allocation approach can provide an explicit decision support mechanism to balance the workloads in light of various production environments to enable an equitable basis for performance evaluation to foster constructive competition among the fabs.
Revisiting dual-role factors in data envelopment analysis: derivation and implications
(2014-07-03)
Chen, Wen-Chih
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Data Envelopment Analysis (DEA) is a mathematical programming method to evaluate relative performance. Typical DEA studies consider a production process transforming inputs to outputs. In some cases, however, some factors can be both inputs and outputs simultaneously and are termed dual-role factors. For example, research funding can be an input that strengthens a university's academic performance and the actual funds can be an output. This article investigates the problem of how to incorporate dual-role factors in DEA. Rather than proposing an ad hoc evaluation model directly, this article considers the concept of "joint technology," two individual production processes acting in common by summarizing the intuitive thinking. The efficiency evaluation models, based on variant assumptions, thus can be axiomatically derived, validated, and extended. How to determine the input/output tendency of a dual-role factor based on the evaluating results is shown and explained from different aspects. It is concluded that the tendency is a property on the projected boundary, not the data point itself.
Selecting an E-Scrap Reverse Production System Design Considering Multicriteria and Uncertainty
(2008-10-01)
Chen, Wen-Chih
;
Hong, I-Hsuan
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
A reverse logistics and production network that deals with recycled material flows has become essential due to the growing concern about the environmental impact of disposed waste and the economic value of recovered materials. Reverse logistics infrastructure design is typically based on tradeoffs between different criteria and faces challenges posed by uncertain system parameters such as the reusability percentage and total supply of end-of-life products. This paper presents a novel method for selecting alternative infrastructure designs to effectively and systematically handle multicriteria cases without subjective weight determination for different criteria. The proposed method, in practice, helps decision makers evaluate and select a design from a pool of alternatives proposed by contractors who place bids for public tenders where the bids include infrastructure design information and associated performance estimates under different uncertain system parameters.
The brand-new high density "NCF=-type compliant-bumped COG" in high resolution LCD
(2007-01-01)
Chang, Shyh-Ming
;
Kao, Kuo-Shu
;
An, Chao-Chyun
;
Chen, Ming-Yao
;
Tsang, Jimmy
Non-Conductive-Film (NCF) bonding method ensures the micro-order direct bonding between the IC electrode and circuit substrate electrode. The binding force of the applied adhesive achieves electrical connections between the bumps on the IC chip and the electrodes on the substrate. The stress analysis results are used to identify the appropriate temperature range for the given NCF bonding structure. Both analytical and experimental results demonstrate the feasibility of using the compliant bumps to achieve a high compressive stress and low as well as stable connection resistance at various environmental temperatures.
The dynamics of performance space of Major League Baseball pitchers 1871-2006
(2010-12-01)
Chen, Wen-Chih
;
Johnson, Andrew L.
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
A central decision-maker, the principal, employs performance evaluation criteria consistent with an organization's overall goal(s) to measure the effectiveness of the agents who execute decisions and implement strategies within a specified period. The dataset of performance criteria spanning the performance space will change over time to reflect the principal's strategic modifications. This paper applies a Data Envelopment Analysis (DEA) based approach to reveals the dynamics of the performance space of Major League Baseball (MLB) pitchers with minimum subjective judgment imposed on the data. The proposed approach is applied to data on MLB pitchers from 1871 to 2006. We conclude that many of the findings are consistent with the observations of baseball's experts. The approach also suggests new directions for investigating a large dataset to identify revealed preferences or strategies by using historical and modern observations.
The dynamics of performance space of Major League Baseball pitchers 1871-2006
(2010-12-01)
Chen, Wen-Chih
;
Johnson, Andrew L.
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
A central decision-maker, the principal, employs performance evaluation criteria consistent with an organization's overall goal(s) to measure the effectiveness of the agents who execute decisions and implement strategies within a specified period. The dataset of performance criteria spanning the performance space will change over time to reflect the principal's strategic modifications. This paper applies a Data Envelopment Analysis (DEA) based approach to reveals the dynamics of the performance space of Major League Baseball (MLB) pitchers with minimum subjective judgment imposed on the data. The proposed approach is applied to data on MLB pitchers from 1871 to 2006. We conclude that many of the findings are consistent with the observations of baseball's experts. The approach also suggests new directions for investigating a large dataset to identify revealed preferences or strategies by using historical and modern observations.