Browsing by Author "Wei, Ching-Kuo"

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A study of developing an input-oriented ratio-based comparative efficiency model
(2011-03-01)
Wei, Ching-Kuo
;
Chen, Liang-Chih
;
Li, Rong-Kwei
;
Tsai, Chih-Hung
;
工業工程與管理學系
Data envelopment analysis (DEA) is a representative method to estimate efficient frontiers and derive efficiency. However, in a situation with weight restrictions on individual input-output pairs, its suitability has been questioned. Therefore, the main purpose of this paper is to develop a mathematical method, which we call the input-oriented ratio-based comparative efficiency model, DEA-R-I, to derive the input-target improvement strategy in situations with weight restrictions. Also, we prove that the efficiency score of DEA-R-I is greater than that of CCR-I, which is the first and most popular model of DEA, in input-oriented situations without weight restrictions to claim the DEA-R-I can replace the CCR model in these situations. We also show an example to illustrate the necessity of developing the new model. In a nutshell, we developed DEA-R-I to replace CCR-I in all input-oriented situations because it sets a more accurate weight restriction and yields a more achievable strategy. (C) 2010 Elsevier Ltd. All rights reserved.
A study of optimal weights of Data Envelopment Analysis - Development of a context-dependent DEA-R model
(2012-03-01)
Wei, Ching-Kuo
;
Chen, Liang-Chih
;
Li, Rong-Kwei
;
Tsai, Chih-Hung
;
Huang, Hsiao-Ling
The weight is one of the main issues of Data Envelopment Analysis (DEA), and relevant theoretical research indicates that many DEA mathematical models include redundant restraints on weight, resulting in underestimated efficiency, pseudo inefficiency, and difficulty in representing specific Input/Output relationships. This study proposes a context-dependent DEA-R model to address shortcomings resulting from redundant restraints on the weights of an efficient decision making unit (DMU), and converts the optimal weight to analyze the influences of redundant restraints on weights. The evaluation results of Taiwan medical centers show that the efficiency of the DMU is underestimated and pseudo inefficiency may occur due to redundant restraints on weight. Moreover, optimal weights are used as variables to conduct cluster analysis in order to determine the information of the weights. The results of cluster analysis indicate that it can assist DMUs in understanding the relationships between DMUs, and contribute to the development of a unique survival strategy for hospitals. (C) 2011 Elsevier Ltd. All rights reserved.
Exploration of efficiency underestimation of CCR model: Based on medical sectors with DEA-R model
(2011-04-01)
Wei, Ching-Kuo
;
Chen, Liang-Chih
;
Li, Rong-Kwei
;
Tsai, Chih-Hung
;
工業工程與管理學系
Data Envelopment Analysis (DEA) is one of the best-known efficiency evaluation methods due to its advantages in selection of weights. Many research papers have extensively discussed the issue of weight restrictions, rather than those implied in the model itself. However, this often leads to a failure to represent the relations of certain weights, as well as underestimation of the efficiency of Decision Making Units (DMUs). When analyzing the medical sectors of Taiwan with the developed models and CCR, it is found that efficiency underestimation by efficient DMUs is more serious than that of inefficient DMUs. In addition, underestimation occurs when weights are concentrated in the same output, however, every output of referenced DMU is the same times of corresponding output of targeted DMU. (C) 2010 Elsevier Ltd. All rights reserved.
Using the DEA-R model in the hospital industry to study the pseudo-inefficiency problem
(2011-03-01)
Wei, Ching-Kuo
;
Chen, Liang-Chih
;
Li, Rong-Kwei
;
Tsai, Chih-Hung
;
工業工程與管理學系
Because of the unreasonable and unnecessary weight restriction assumption, a barely noticeable deficiency in pseudo-inefficiency occurs at times when applying a CCR model. The CCR was the first model designed for Data Envelopment Analysis (DEA); it remains its most popular model. To detect this type of unobvious deficiency, this study compared the following; the efficiency score and optimal weight set of an input oriented CCR model (CCR-I); the model with a weight restriction assumption; an input-oriented ratio-based DEA model (DEA-R-I); and the model without it. In this case study of hospitals, pseudo-inefficiency was discovered and the reason behind it determined. Further, this study proved that the DEA-R-I is a valid model. Because DEA-R-I is valid and without a weight restriction assumption, this study puts forward the DEA-R-I as a capable substitutive model for CCR-I in order to avoid pseudo-inefficiency. (C) 2010 Elsevier Ltd. All rights reserved.